A Bit is a digit in the binary
number system. It can have two values, 0 or 1. In computer RAM
memory, a bit is a small electrical switch which is either on (value 1) or off (value 0).
However bits don't exist individually but in groups of 8 and that is a byte. So one Kilobyte of RAM = 1024 bytes or 8192 bits.
All CPUs have instructions to manipulate bits, such as rotating or shifting bits left or right in RAM or in a Register.
4610 = 001011102. If this is shifted left one bit (with a 0 bit put into the rightmost bit) the value is 010111002 which is 9210. A left shift of one bit is the same as multiplying by 2. A right shift is the same as deviding by 2.