Creating custom page templates in WordPress is easy!
Its just following line of code which you need to put at the start of page template file.
let’s start creating a page template called ‘project.php’ and put following line of code at start of this file and using FTP client upload this file to your theme folder.
Template Name: Projects template
Now at your new page screen in page attribute widget you will templates, our recently uploaded template should appear here. if you will select this page template for your page and after hitting publish and viewing newly added page will show you a blank page. now you can start editing this page template file (project.php) and can add contents and code here what you want show for this specific page or pages. you can use this Custom template page to assign to different pages through page edit screen. there are lot things which you can do using this custom page template like adding a form, design different than other pages and huge amount of PHP code. this all is easy using Custom page templates.
WordPress also have lot of other alternatives to do this, but this one is much easy to adapt for even non-tech person. actually how it works? WordPress looks for several Page template files in your active WordPress Theme based upon the Template Hierarchy. and in that hierarchy Page’s selected “Custom Page Template” stand first, so that will be used.