A bitwise operation operates on each bit, bit for bit, rather than on the numeral as a single unit.
Bitwise operations are often faster than regular arithmetic operations.
puts ~1011 # bitwise not or complement
puts 1011 | 1010 # bitwise or
puts 1011 & 1010 # bitwise and
puts 1011 ^ 1010 # bitwise exclusive or
puts 1011 << 1 # shift left
puts 1011 >> 1 # shift right