Variables

what is a variables? In programming, a variable is a value that can change, depending on condition passed to the program. Typically, a program consists of instructions that tell the computer what to do and data that the program uses when it is running.
Variables problems:

a=input("enter your name: ")
b=input("enter your last name: ")
d=input("enter your age: ")
c=str(a)+str(b)
e = int(d)
print("answer",c)