A system is a set of things working together as a part of a main mechanism or network. It’s a complex meaning to understand something easy to see.
Natural and human-made systems & Process and transformation process are part of this world. A system is going to be something that is working in a whole concept of engine, if you don’t have this engine working, your are not going to have the system working.
A system could be, for example, parts of your laptop: you laptop is made by different components, and everything together is going to create a whole system that is going to make your machine works. An OS (Operating System) for your mobile, another example, many parts and many physical and nonphysical components are going to create the world for let you and your environment use the phone as you may know.
I don’t want to bother you, so if this text doesn’t make you any sense or you are looking for any specific result, you can google it too :D