An add-on is a small mini-program that runs together with the application program and extends its functionality. There are many add-ons that extend the well-known application programs with security functions, reporting functions and graphics functions.
An add-on is an added optional module that extends the existing hardware functionally or the programs capabilities. Such an add-on or plug-in can be added or removed at any time without affecting the original functions. Add-ons can add toolbars or support various graphics formats, animation formats and video formats. The added plug-ins have their own data structure, which is not a part of the software into which it is integrated.