You can find literally hundreds of document formats online, and countless more have passed into obsolescence. That can make it extremely difficult to decide which format to use and when. Fortunately, you’ll probably only ever have to use a handful in your daily life.

Take a look at these five and ask yourself if they’d satisfy the needs of whatever project you currently find yourself faced with.

1. Plain Text Format (TXT)

Perhaps the simplest format that’s still in use, plain text files don’t come with any embedded fonts or style hints. That means you can open them with almost any tools, so they’re perfect for situations where you need to make sure the other party can open your file no matter what. Nano and other command line tools are perfect for editing TXT files, but you can even use pretty much any modern browser to view them. Consider TXT format when file size is the most important consideration.

2. Portable Document Format (PDF)

Due to the flexibility of Adobe Acrobat and the fact that PDF files can be read on countless different devices, this has become one of the most popular formats on the web. You’ll want to use it almost any time that you share a document in the cloud or via email. PC users can compress PDF files using the Acrobat suite and this will normally make them small enough that they could even be transferred as a multimedia text message through a smartphone.

3. Word Document (DOC/X)

Whether you want to produce business correspondence or type out professional-looking letters that are ready to be printed out, consider the DOC or DOCX file structure. The fact that there are many alternative solutions that can work with DOC files, such as AbiWord, have helped to popularize it. By using a virtual printer, you can also convert it to PDF or several other formats as well, which should help to provide an even greater degree of interoperability with those who use other computing devices.

4. Rich Text Format (RTF)

In situations where you have to send style hints but you don’t know what kind of computer the other party has, you might want to consider RTF. This format is essentially like a Word document, but it’s designed to be as vendor-neutral as possible. Support for it is built into Windows, but Macintosh and Linux users can rely on the TextEdit app to get the same functionality.

5. PowerPoint Presentation (PPT/X)

Anytime that you want to make a slideshow to present information in a convenient manner on a projection screen or in an online video, consider using PowerPoint’s own document format. Since it’s hard to share these files with those who don’t have access to PowerPoint, however, so you’ll want to export them as PDF files before you post them online. That will ensure that even users without access to a standalone PowerPoint app will be able to flip through your slides.