What is the name of the cable that connects a Wi-Fi router to a computer? A complete guide.

Many users face a situation where they need to ensure the most stable connection between their computer and the internet, and the first thing they look for is the name of the cable that connects their Wi-Fi router to their computer. In everyday life, this cable is often mistakenly referred to simply as an "internet cable," but the technically correct name is quite different. Understanding the correct terminology will help you avoid confusion when purchasing equipment in a store or when communicating with your provider's technical support.

The main name you need to remember is Ethernet cableThis is the designation for the wired local area network standard commonly used to connect computers, laptops, game consoles, and TVs to a router. However, in professional environments and among installers, you'll most often hear a different name: twisted pairIt comes from the internal structure of the cable, where copper wires are twisted together in pairs to reduce electromagnetic interference.

It's important to note right away that, although the router broadcasts a wireless Wi-Fi signal, the physical connection to it is made through this network cable. The RJ-45 network cable is a universal standard for wired connections between devices in local area networks around the world. Unlike a wireless signal, which can be affected by walls, microwaves, and neighbors' routers, a wired Ethernet connection ensures minimal latency (ping) and maximum data transfer speeds, which are critical for online gaming and watching 4K video.

Technical name and structure of the cable

Digging deeper into the technical details, "twisted pair" isn't just a name, but a description of the physical structure. Inside the outer insulating sheath are eight thin copper wires twisted in pairs. This twisting is necessary to compensate for external electromagnetic interference and crosstalk between the pairs themselves. There are several categories of these cables, designated by acronyms. CAT (Categories) that determine the maximum line capacity.

The most common type for home use is category A cable. CAT5eIt is capable of transmitting data at speeds of up to 1 Gbps over distances of up to 100 meters, which fully covers the needs of most residential internet service providers. For more powerful networks requiring 10 Gbps speeds, category 1 cables are already being used. CAT6 and higher, which have thicker insulation and are often equipped with additional protection against interference.

⚠️ Caution: Don't confuse cable categories. Using an older CAT5 cable (without the "e") will limit your speed to 100 Mbps, even if your ISP plan and router support 1 Gbps.

Cable construction can be shielded or unshielded. For standard apartments, where the cable is laid indoors and not near powerful electrical appliances, the unshielded version is sufficient. UTP (Unshielded Twisted Pair). If the cable is to be installed in industrial facilities or along power lines, a shielded cable is required. FTP, which has an additional layer of foil to protect the signal.

Connectors and Jacks: What is RJ-45?

When we talk about the name of a cable, we mustn't forget about the connector at the end. The plastic tip that plugs into a computer's network card or a router port is called a connector. RJ-45This is an international standard that ensures compatibility between equipment from different manufacturers. Visually, it resembles an RJ-11 telephone connector, but is larger and has eight contacts instead of four or six.

The process of securing the cable inside the connector is called crimpingA special tool called a crimper is used for this. The order of the colored wires inside the connector must strictly correspond to one of the diagrams (usually the T568B diagram), otherwise the connection will either not work or will be unstable and suffer packet loss. Factory-made cables sold in stores are perfectly crimped, but errors are common when making your own cable.

• 🔌 RJ-45 has characteristic latches that secure the cable in the port and prevent it from accidentally falling out.
• 🔌 Inside the connector there are gold-plated contacts, ensuring reliable electrical contact with the network card.
• 🔌 There are angled connectors that allow you to connect the cable in hard-to-reach places where a straight connector won't fit.

It is important to understand the difference between a connector and a port. RJ-45 - this is the name of the plastic tip on the cable, and the socket into which it is inserted on the body of the device is called Ethernet port or a LAN port. Modern routers typically have several such ports (from 1 to 8), allowing you to connect multiple devices simultaneously via wires, creating a local area network.

Differences between Ethernet cable, USB cable, and other cables

Beginners often confuse network cables with other cables, especially USB cables used to connect peripherals. The main visual difference between an Ethernet cable is its thickness and cross-sectional shape. Twisted pair cables are typically round in cross-section and noticeably thicker than USB cables. Furthermore, the RJ-45 connector is wider and has a different pin shape compared to the rectangular USB Type-A connector or the oval Type-C connector.

Another important difference lies in the functional purpose. USB (Universal Serial Bus) is designed to connect external storage devices, keyboards, mice and modems to a computer, transmitting data sequentially. Ethernet Designed exclusively for network communication and packet data transfer between network nodes, the USB port prevents physical insertion of a USB cable into the network port thanks to the different connector geometries, protecting the equipment from damage.

There is also confusion with telephone wires. Older telephone cables use a connector. RJ-11, which is visually similar to RJ-45 but smaller. If you try to insert a phone cable into the network port, it may fit, but the connection won't work. In the worst case, you could damage the port's contacts, as the pinouts are different.

Cable categories: which one to choose for your home

When choosing a cable to connect your computer to your router, it's important to pay attention to the markings on the outer jacket. As mentioned earlier, the key parameter is the category. For home use in 2026, the gold standard is CAT5eThis cable supports gigabit speeds and is inexpensive. There's little point in buying more expensive options for casual surfing and watching movies, although a little extra durability is always a good thing.

If you are planning to build a serious home network with a server, 4K video surveillance, or just want to build something “for growth”, you can consider category cables CAT6They have thicker wires and often a plastic spacer inside, which keeps the pairs apart, improving performance at high frequencies. However, it's important to remember that to achieve speeds above 1 Gbps, all your equipment (router, PC network card, switches) must also support the Gigabit Ethernet standard or higher.

⚠️ Note: Cables marked CCA (Copper Clad Aluminum) are made of aluminum coated with copper. They are cheaper, but more fragile and have poor signal conductivity. For permanent wiring, it is better to choose cables made of pure copper (OFC).

It's also worth paying attention to the outer sheath material. For installation inside residential buildings, a cable with a sheath made of PVC (polyvinyl chloride). It's flexible and inexpensive. If the cable is to be installed outdoors or in fire-prone areas, there are special modifications: PE (polyethylene) for the street - it is not afraid of ultraviolet radiation and frost, and LSZH (Low Smoke Zero Halogen) - it does not emit toxic smoke when burning and is required for installation in offices and public buildings.

Is it possible to extend the network cable?

Yes, there are special RJ-45 connectors (couplers) for this purpose. However, each connection is a potential point of signal loss. It is not recommended to chain more than two connectors. It is better to use a single, continuous cable of the required length.

Instructions: How to properly connect a computer to a router

The process of physically connecting a computer to a router using an Ethernet cable is extremely simple and doesn't require any specialized knowledge. The key is to follow the steps carefully and be careful with the plastic connector clips. Before handling any wires, it's a good idea to ensure that the equipment isn't at risk of short-circuiting, although modern ports are protected.

First, find a group of ports on the back of your router, usually labeled as LAN or EthernetThey are often numbered (1, 2, 3, 4). Don't confuse them with the port. WAN or Internet, which is usually highlighted in color and is used to connect the cable from the ISP. Insert one end of the cable into one of the available LAN ports until you hear a distinctive click.

The other end of the cable connects to the network card of your computer or laptop. On desktop PCs, the connector is located on the back of the system unit; on laptops, it's on the side. If your Ultrabook doesn't have a built-in RJ-45 port, you'll need an adapter. USB-to-Ethernet.

Once connected, check the LED indicators next to the port. Typically, one is solid (power/link), while the other is blinking (data transfer). If the indicators don't light, try tightening the connector or replacing the cable. In Windows, you can check the connection status by pressing Win + R and entering the command ncpa.cpl, which will open the network connections window.

ipconfig /all

This command, entered into the command prompt, will display detailed information about your network adapter, including the physical address (MAC) and assigned IP address. If the "Environment" column says "Network cable not connected," there is no physical connection.

Possible problems and their solutions

Even with high-quality equipment, problems with wired connections sometimes arise. One of the most common causes is damaged cable conductors. Twisted pair cable, although seemingly durable, is sensitive to strong bends, especially where it exits the connector. If you frequently move your computer case or laptop, the cable may break inside the insulation, resulting in connection loss or speed drops to 10 Mbps.

Another problem is contact oxidation. In high-humidity or dusty conditions, the contacts inside the RJ-45 port can oxidize. This manifests itself as an unstable connection, which sometimes appears and sometimes disappears. In such cases, gently cleaning the port with compressed air or using a contact spray can help, but this should be done with the device powered off.

• 🛑 Wire break: The network operates at low speed (100 Mbps instead of 1 Gbps) because only 4 wires are used instead of 8.
• 🛑 IP conflict: It is rare, but it does happen that two devices on a network are assigned the same static address, which blocks the operation of one of them.
• 🛑 Invalid driver: If nothing happens after connecting, it is possible that the network card driver is not installed in the system.

To diagnose cable integrity, professionals use a device called LAN testerIt consists of two parts: a base and a remote module. By passing a signal through each of the 8 wires, the tester indicates whether all pairs are intact and crimped correctly. If the indicators light up out of order (e.g., 1-2-3-5...), the colors were mixed up during crimping.

⚠️ Caution: If you're using Power over Ethernet (PoE) to power cameras or access points, make sure your cable is capable of transmitting power. Cheap CCA cables may not handle the current and may melt.

FAQ: Frequently Asked Questions

Can you use a telephone wire instead of a network wire?

No, you can't. A telephone cable only has four conductors (sometimes two) and an RJ-11 connector, which is smaller than an RJ-45. Even if you manage to physically insert it (which is difficult), you won't be able to transmit data at high speeds, since Gigabit Ethernet requires all eight conductors.

Does cable length affect internet speed?

Within the standard (up to 100 meters for twisted pair), the length of a high-quality cable doesn't affect speed. The signal attenuates, but within 100 meters, this attenuation is compensated for by the network card's electronics. Problems can only arise if this length is exceeded or if very low-quality cable is used.

Do you need to buy expensive CAT7 cable for your home PC?

For 99% of home users, CAT7 cable is overkill. It's stiff, expensive, and requires shield grounding to function properly. Standard CAT5e or CAT6 are perfectly adequate for speeds up to 10 Gbps over short distances.

Why is the indicator light orange instead of green?

The color of the LED often indicates the connection speed. Green might indicate 1 Gbps, while orange (or yellow) might indicate 100 Mbps. This could indicate a faulty cable (only four wires are working) or that the router/card port doesn't support gigabit speeds.