A PowerPoint Template is a file that can contain commonly used settings to make producing future PowerPoint Presentations and Shows easier. POTX PowerPoint Templates are different than the POT version in that they use the Microsoft Office Open XML format.
HTML is a Web format file. HTML source code can be changed in a text editor. HTML files are being developed for future use in the users web browser, allowing you to format text, images and other materials required sites. File with this format use tags to build web pages. HTML code is parsed Web browser and usually not visible to the user.