Function
A function is a reusable block of code that has inputs, arguments, and can return a value when it is called.
abs(-23) # 23 Here, the function name is abs. It is passed in the value of -23, and returns 23 when called with abs().
Some functions can be passed a variable number of arguments.
max(2, -3, -6, 10, -4) # 10
max(1) # 1 We can nest function calls to evaluate sophisticated expressions.
min(abs(max(-1, -2, -3, min(4, -2))), max(5, 100)) # 1