What is conio

Answer 1

conio.h (Console In Out) is another form of stdio.h (Standard In Out). Like DaemonThread said, it outdated and was usually used on Linux. C and C++ compilers may include it in their header lists, but it's highly unlikely in this day and age that they still use it.

Answer 2

It's a header file.

Answer 3

It's this outdated header file that let you manipulate the console. If you use the compiler that SoloLearn recommends, you probably don't have conio available.