A plug-in, also known as an add-on or plug-in, is an additional module dedicated to a given computer program, thanks to which the output product is expanded with new functionalities. Plugins are available both as commercial and open source software. In the case of paid programs, they are usually created by the software manufacturer and they are usually additionally paid. For open source programs, the API must be available and documented to create plugins. The advantage of transferring additional functionalities to plugins is not burdening the base program with niche functions. Thanks to this, the user installs only those that he needs, and the program works more efficiently using the optimal amount of resources.