A bit is a binary representation; either 0 or 1 and combination of bits make up the bytes, kilobytes and so on, where:
1 Nibble = 4 Bits
1 Byte = 8 Bits
1 Kilo Bytes (KB) = 1024 Bytes
1 Mega Bytes (MB) = 1024 KB
1 Giga Bytes = 1024 MB
The more memory you have in general, the more each program can do. Memory is measured in small groups of data called bytes. Each byte consists of eight bits. The byte is the basis of all the measures dealing with the computer.