For those computer programs that support customizations, there are certain add-ons created for customers with integrating with the computer program and those add-ons or piece of a software component is called a plug-in.
The plug-ins are designed with the vision to provide personalization and customization capabilities to a software computer program. It is also a great way to increase the capabilities of a platform that can be scaled to meet customer expectations.
Many e-commerce platforms that serve a larger audience from different business domains or verticals include plug-ins in their marketplace. Plug-ins can also be a part of product lists such as browsers and websites and they can either be paid or free.