Tex is a computer program that can typeset text and mathematical formulae. Latex is a markup language that uses tex as its typesetting engine. Basically this allows the user to embed commands within a text file that can be interpreted by latex to produce a high quality typeset documents. TexStudio is a cross-platform latex integrated development environment (IDE) for windows, OSX and linux that means that you can both edit text files and produce typeset documents all in one program. Best of all the program is free and available to download, click here for my guide on setting it up on Windows.
Click on the start menu at the bottom of the page and enter 'texstudio' in the search bar, then click on the application. Now select
File->New from Template...and choose to create an article.