Where c anc c++. Is used?

Answer 1

C++ - games, desktop applications (QT framework is so popular and one of the best for crossplatform apps), any big application, which require high perfomance.
C - low level applications, any utils, working with operation systems, with network and etc. (c++ also used for it).
Both - sometimes used with other languages to improve perfomance by their ability of working with memory more directly than other langs like python, php...

Answer 2

big apps(software) huge thinks like AI