hello(hello computers are fundo you see what this doesthe two print statements from the hello function definition are executed in sequence you may be wondering about the parentheses in the definition and use of hello commands can have changeable parts called parameters (also called argumentsthat are placed within the parentheses let' look at an example of customized greeting using parameter first the definitiondef greet(person)print("hello"personprint("how are you?"now we can use our customized greeting greet("john"hello john how are yougreet("emily"hello emily how are youcan you see what is happening herewhen using greet we can send different names to customize the result you might also notice that this looks similar to the print statements from before in pythonprint is an example of built-in function when we call the print functionthe parameters in the parentheses tell the function what to print we will discuss parameters in detail later on for the time being the important thing to remember is that the parentheses must be included after the function name whenever we want to execute function this is true even when no parameters given for exampleyou can create blank line of output using print without any parameters print(but if you type just the name of the functionomitting the parenthesesthe function will not actually execute insteadan interactive python session will show some output indicating what function that name refers toas this interaction showsgreet print