PowerPoint is a software created by Microsoft to assist people creating slideshows. The word PowerPoint (often abbreviated to ppt) is also commonly used to describe the final product of this software — PowerPoint presentation file.
Microsoft PowerPoint is a part of MS Office Suite, containing among others also a word processor (Word) and a spreadsheet program (Excel).
Final PowerPoint presentation consists of series of single slides encapsulating consecutive parts of the message. The ability to divide the whole communication into singular, easy to absorb parts is one of the reasons why people often use PowerPoint slides as a substitute of longer forms, such as text documents.
Due to an extensive use in business world, presentations evolved to be a major means of communication. PowerPoint templates encapsulate good practiced in design and content selection, thus allowing users to save time while working on their slides. Read more about presentation templates here.
MS PowerPoint is available also on Macintosh Operating System, as a part of Office for Mac.
Main alternatives for creating slide-based presentations are Apple Keynote (available only for Mac users) and Google Slides.
PowerPoint presentations come in 2 main formats: .pptx files are a modern presentation format, used by Microsoft PowerPoint since version 2007. They use Microsoft Office Open XML format, which means they are easy to read by other programs, like Apple Keynote or Apache OpenOffice. Older .ppt files were used before that and now are considered a legacy format.
https://products.office.com/en/powerpoint — official Microsoft product site