Using PHP in Web Pages

can someone here steer me in the correct direction? heres what i want to do. (im sure its possible)?? i dont want to have to edit every web page when i change something. can i make multiple pages, (say a header, footer, links, maintext, and then use PHP to call those pages up and put them in certain places in a web page? Without have to set up html frames? Maybe just add a line of code to place it dynamicaly or something.... thanks, dave