IP Address(IP)
A unique numerical identifier assigned to every device connected to a network so it can communicate with other devices.
What is an IP Address?
In one sentence: IP Address is like your home address in the internet world — every device has a unique address so others can find it.
Let me put it simply. When you want to send someone a letter, you need to know their address, right? Internet works the same way. Every device (computer, mobile, server, even a smart refrigerator!) has a numerical address called IP Address. Without this address, no one can send data to you.
We have two IP versions:
IPv4: Older, consists of four numbers like 192.168.1.1. Each number can be between 0 to 255. The problem is that IPv4 only has about 4 billion addresses which is running out.
IPv6: Newer, consists of numbers and letters like 2001:0db8:85a3:0000:0000:8a2e:0370:7334. This version has many many more addresses and solves the address shortage problem.
Public and Private IP:
Public IP: The address that the internet sees. Like your home address that the postman sees. Your ISP (internet company) gives you this address.
Private IP: The address that's only used in your home or company internal network. Like 192.168.x.x that you usually see on modems. These addresses are not accessible on the internet.
Why is it important for security?
Because attackers can use IP to identify your approximate location, scan your ports, or even launch DDoS attacks. Also there's IP Spoofing where the attacker fakes their IP to keep their identity hidden.