I like how although the illustration is very simple, there are still a lot of detail in the garment and face. Shading has been conveyed through darker and thicker lines contrasting with thinner lighter lines, which i also really like.
Different file types serve various purposes. The pros and cons of a particular file type are what may make it more useful over another. A PNG file may not be the best choice when you are looking to keep file sizes low and have an image that has full cover
Knowing what file format to use can make a huge difference. In certain cases you want to use a certain file format to save the work you've done. Different file types are used for different programs and different types of work.
This file type list and cheat sheet by guides you through the appropriate file types to use for various digital projects. It goes over the common use cases, what you should know, and technical details of many of the digital file types.