What is “bit padding” or “padding bits” exactly?

Question

I do not want to molest you with this, but i just can not find anywhere in the internet a well-described explanation for what "bit padding" really is, as well as n

Answer 1

So imagine you have an 8 bit number, it's an uint8_t, and its value is set to 4. This would probably be stored as a = 0000 0100. Now, let's say you wish to convert this into a 16 bit number. What would happen? You have to assign some values to 'new' bits in this number. How would you assign them? You can't randomly assign zeros or ones, value of original variable will change. Depending on architecture etc. you have to pad value with extra bits. In my case, that would mean additional eight extra zeros be added in front of original MSB (most significant bit), making our number a = 0000 0000 0000 0100.

Value is still 4, but now you can assign anything in [0, 2^16) range, instead of [0, 2^8) range.