it is really useful to understand binary. misunderstanding of how data are encoded and binary logic are at the source of many difficult to troubleshoot bugs!
Yes, 0s and 1s are the languages of computer and while you are programming if ur dealing with like data compression or encription algorithms ..., you will need to have the know how.
Which programming languages?
Most "higher-level" programming languages, typically you will not need it. Depends on what you are doing.
Like are you doing web-design? You will never use it.
