The first line of the program #include is a preprocessor command. Which tells a C  compiler to include stdio.h file before going to actual compilation.

The next line int main() is the main function where the program execution begin.

The next line int a = 10; is the place where we are intializing a value in to a variable and also explaining that which type of data we are storing ina variable.

The next line printf(……….)  is another function available in C which causes the to print the value we have given in a variable.

 The next line  return 0;  terminates the main() function and returns the value 0.