Why the Smallest Operable Data Type in Most Programming Languages Is One-Byte Sized?
Most instruction sets contain instructions that modify a single byte, but not instruction that modify a single bit and so higher level languages tend to reflect that.

Though modern high level languages include what is effectively a bit type, called boolean. Usually, it can only take two value (true or false), but a boolean requires a whole byte for storage.

If you need to store many bits, what you can do is to use a specialized data structure, which internally uses bytes or integers for storage (and so it stores 8 or more bits in a single underlying element). Such data structures include std::vector&lt;bool&gt; in C++ and BitArray in .Net.