Base 10 (a.k.a. decimal) is the numeric system which most people using in daily life.
For the digital logic or computer system in nowadays, it would use binary instead. Binary only have two values, 0 and 1. For any number that larger than one, it should be represented by two digital.
A number represented as binary has longer length comparing with decimal. Usually, hexadecimal is used for written down in the program.
Prefixes is add for represent the binary and hexadecimal in the source code. Here is the example in C.