You need to #include the header file that contains the missing function's declaration.
it is sqrt in header math.h
conio.h is a library function which is predefined in the header file and 'clrscr();','getch();' and many other functions come under this.
That means, the header of a function. The header is the top part, before the opening braces.
Java does not require header files like C/C++.
No predefined 'header' function in the standard C libraries. There are header files, if that's what you mean.
No explicit limit, you can use so many header files as you want.
Yes.
The std::pow() function can be found in the <cmath> header.
The sequence number, acknowledge number, and Window fields.
Frame Header - Network Header - Transport Header - Data - Frame Trailer
A haeder is a text-file, meant to include (#include) into a source-file. Usually it contains variable and function declarations, constants, type-definitions, documentation.
Header files are used to have declarations. It is simple to include a single header file than writing all the needed functions prototypes.