| Full Name | Portable Network Graphics |
| Extension | PNG |
| Type | Image |
| Mime Type | image/png |
| Format | Binary |
A PNG file is a two-dimensional image file format often used to store high-quality logos, icons, and other imagery. PNG files first emerged in the early 1990s as an alternative to the GIF format, which was in widespread use at the time. PNG files have garnered support over the years to at least equal or surpass that of the GIF format. You will find all modern image editing or viewing applications will support PNG files.
Part of the success of the PNG format is its use of special compression techniques that allow a high-resolution image to be compressed into a very small file size. The compression used in the PNG format is lossless compression, ensuring no image detail is lost when an image is saved to the PNG format.
Uses
The PNG format is ideally suited for storing images that require no loss of detail or have transparent areas, such as company logos and computer graphics icons. It is not suited for storing general photos as, due to the nature of the compression, it will result in very large file sizes. Other formats, such as JPEG, use a lossy compression method, and this format is better suited to full-color photographic images.
| Full Name | Standard Triangle Language |
| Extension | STL |
| Type | 3D Model |
| Mime Type | application/vnd.ms-pki.stl |
| Format | Text |
The STL file format is used for storing 3D models and is a common format for distributing 3D printable models. STL files emerged in the 1980s as a format for storing a 3D mesh as a simple list of triangles. Due to its age and simplistic format, it has gained widespread support within 3D modeling and CAD applications.
As a result of the simple file format and its widespread support amongst 3D editors, the STL format has found itself as the format of choice for the distribution of 3D printable objects. There are many websites that offer 3D printing downloads in the STL format.
Mesh Geometry
As mentioned, STL files make use of a simple structure for containing the 3D mesh data. The 3D model is stored as a continuous list of triangles, with each triangle containing three vertices specifying the location in 3D space of the triangle, which, along with a single vector normal, is all that is required to render the model contained within the STL file. There are two formats of STL files: plain text and binary. When used with large and complex 3D models, the text format leads to very large file sizes and should be avoided, with the binary format offering more efficient storage of the mesh data.
