a=5
b=7
c=a+b
print(c)
a is refering to 5 which means wherever a is used its value would be 5
b is refering to 7 which means wherever b is used its value would be 7
c is refering to addition of a and b which is 12
print() is a standard output function, print(c) will send value of c, 12 on standard output device