What are the most used file types?
Speaking from experience the most commonly used file types are AI, EPS, PDF, PNG and JPG.
These file types are used for sharing, web, printing and edits.
You may need to share files between friends or colleagues. The easiest, fastest and most compact files to do this are JPGS. Just note there will be some quality compromised as a result of the file compression.
Another file type that is easy to share are PDF files. These file types can be used by lots of free readers across the web. They are viewable, high quality and in some cases editable.
You will want to share PNG files with your website developer. These files are great for transparent background usage. They are a better quality JPG image and use a much broader color spectrum making this file great for high-quality web graphics.
Vector files are usually required by graphic designers like myself. I primally use Adobe Illustrator so generally I prefer a file that was created in the program. Otherwise an EPS file is sufficient.
So, what is the difference between these file types? See the graphic below!