A TileSet in Godot is a type of Resource. Examples of other resources include Textures, Animations, and Fonts. They are containers that hold a certain type of data, and are typically saved as .tres files.
By default, Godot saves files in text-based formats, indicated by the t in .tscn or .tres, for example. Text-based files are preferred over binary formats because they are human-readable. They are also more friendly for Version Control Systems (VCS), which allow you to track file changes over the course of building your project.
To make a TileSet, you create a scene with a set of Sprite nodes containing the textures from your art assets. You can then add collisions and other properties to those Sprite tiles. Once you've ...
