I think you're still slightly confused yourself, actually. All of the fields below have a great deal of overlap because they are in similar parts of the world
Computer Science: Computer Science is the broad study of computational systems, which can be a little frustrating, because people often use the term to describe some specific subset. If you major in "computer science" at a university, it is not at all clear what you will be studying after a few intro courses until you inspect the curriculum. It is perfectly possible to get a CS degree without studying almost any content from the other fields outlined below. However, all of those terms could possibly be called "computer science" depending on the context.
I (and some others) hold that Computer Science is purely the branch of mathematics that deals with computation. Some people try to keep things less ambiguous by adding the word theoretical before CS to indicate the mathematical field, but this is not always the case. (Take a look at the Computer Science Stackexchange to get a sense of what I would term "CS".)
Software Engineering: The art and science of creating good software.
Information Technology: The field concerned with the hardware and software infrastructure that manages networks and data.
Computer Engineering: a field that mixes Electrical Engineering with Software Engineering.
Mechatronics: a field that combines Computer Engineering with mechanical engineering.