uint256 is perhaps the most used value type in Solidity. And yet you might not be familiar with it if you’ve been writing a high-level language like JavaScript or Python. In this post, I explain what uint256 is in plain English. I will break uint256 down into two parts(uint and 256) and explain each of them.
uint
In Solidity and other languages like C#, int is a signed integer and uint is an unsigned integer.
A numeric variable is signed if it can represent both positive and negative numbers: