STL, an abbreviation for stereolithography, is an interchangeable file format that represents 3-dimensional surface geometry. The file format finds its usage in several fields such as rapid prototyping, 3D printing, and computer-aided manufacturing. It represents a surface as a series of small triangles, known as facets, where each facet is described by a perpendicular direction and three points representing the vertices of the triangle.
Files with PPTX extension are presentation files created with popular Microsoft PowerPoint application. Unlike the previous version of presentation file format PPT which was binary, the PPTX format is based on the Microsoft PowerPoint open XML presentation file format. A presentation file is a collection of slides where each slide can comprise of text, images, formatting, animations, and other media.
You can also convert STL into many other file formats. Please see the complete list below.