In simple terms, the OSI model is a routine, that runs on the backend of your internet and network components, consisting of both physical hardware and software.
Each and every time you use a technological device on a network to request information, go to a website, download a file or document, you are initiating a run-through of the OSI model. When Two devices communicate, a specific set of rules and protocols must be followed to ensure successful communication, and results are met when a request is initiated.
Below we have the Seven Layers describing what each does, and a easy way to remember them.