We can create separate page for each page wordpress, What it means is for example if you have multiple pages in your website. and you are powering each page using "page.php". Then for specific page you can have separate file.
So let's say we have "about us" page, "portfolio" page and "contact us" page and what i want to do i want to display some content only on "portfolio page". We can use conditional statement but i want separate file for "portfolio" page.
then i will create a file for "portfolio" and will name it as "page-portfolio.php".
Now i will paste code from "page.php" to "page-portfolio.php" and will add some content and this content will only appear on "portfolio page". All Done