Four words appear in every network setting — IP address, subnet mask, default gateway and DNS — and most people just copy them without knowing what they do. This guide explains each one in plain words, with one real example running through all of them.
Open any PC's network settings and you will find the same four values staring back. They look technical, but each one does a single simple job. Learn the four jobs once, and screens like ipconfig /all stop being scary forever — plus, half of all 'internet not working' problems become easy to read.
☝️ One command shows all four values on a real PC. The numbers above are examples — yours will look similar but not identical.
Every device on a network needs an address, exactly like every house on a street needs a house number. Your PC, phone, printer and router each carry one. When data travels, it is delivered to an address — never to a device name alone.
An IPv4 address has four numbers separated by dots, like 192.168.1.25. Each number sits between 0 and 255. Home and office networks use private ranges that never appear on the open internet: 192.168.x.x, 10.x.x.x and 172.16.x.x to 172.31.x.x. If your address starts with one of these, you are on a private network — which is normal and correct.
The mask sits next to the IP address and answers one question: which part of the address is the street name, and which part is the house number? In 192.168.1.25 with mask 255.255.255.0, the first three numbers (192.168.1) are the street, and only the last number (25) is the house.
Devices on the same street talk to each other directly. Devices on different streets cannot — their data must leave through the gateway. This single idea explains most 'my PCs cannot see each other' problems.
The mask is also written as a slash number. /24 means 255.255.255.0: the street has 256 addresses in total (0 to 255), of which 254 are usable for devices, because the first (.0) names the street itself and the last (.255) is the broadcast address.
The gateway is the door between your street and the rest of the world. On a home or office network it is almost always your router, and in our example it is 192.168.1.1 — the first usable address on the street.
Your PC follows a simple rule: same street — deliver directly; any other street — hand it to the gateway. That is why a wrong gateway entry kills only the internet, while file sharing with the PC next to you keeps working. The local street never needed the door.
Nobody types 142.250.x.x to open Google. You type a name, and DNS quietly converts it into an IP address before anything loads. DNS is the phonebook of the internet: names for humans, numbers for machines.
This explains a classic puzzle — a website 'not opening' while the internet is actually fine. If the site opens when you type its IP address but not by name, the connection is healthy and only the phonebook lookup is broken. Your DNS server is usually the router itself, or a public one like 8.8.8.8 (Google) or 1.1.1.1 (Cloudflare).
Put it together. You type a website name. DNS converts it to an IP address. Your PC checks the address against its subnet mask: different street, so the data goes to the default gateway. The gateway (router) forwards it to the internet, and the reply comes back to your IP address. Four simple jobs, one smooth trip.
And who gave your PC its address, mask, gateway and DNS in the first place? Almost always DHCP — a service on the router that hands all four values out automatically the moment you connect. That is why most people never type any of this by hand.
The video explains all four with simple examples on a live PC — the fastest way to make these basics permanent.
▶️ Watch Full VideoIt is the address of a device on a network, like a house number on a street. Data is delivered to addresses, so every PC, phone and printer needs one. A typical example is 192.168.1.25 on a home network.
It means the first three numbers of the IP address are the street (network) and only the last number changes per device. This mask is also written as /24. It gives 256 addresses in total, of which 254 can be given to devices.
Local network work — like sharing files with a PC on the same network — keeps working, but the internet stops, because the gateway is the only door out of your local network. A wrong door address means nothing can leave.