File > Export helps you change your presentation into a different format, such as PDF, video, or Word-based handouts. All these options are covered below.
If you simply want to "export" a file (in its current .pptx format) to a different storage system, such as a flash drive, plug that flash drive into your computer and use File > Save As (or Save a Copy) to save to that new location.
You can convert your presentation to PDF or XPS to share with others.
You can turn your presentation into a video file that can be watched without using PowerPoint.
You can create a package for your presentation and save it to a CD or USB drive so that other people can watch your presentation on most any computer.
If you want to use the editing and formatting features of Word, you can work on and print your handouts using Word.
Change File Type is the same feature as the traditional Save As command. You select the underlying type of file you want, then click the Save As button. The original file is kept in its current format and closed, and a new copy of it is opened and saved in the format you've chosen.
(This feature is available to Microsoft 365 subscribers who are part of an organization.)
After you save your presentation as a video, you can upload the video to a video-sharing site named Microsoft Stream that only people in your school or organization have access to. Those people can watch the video in a browser.