Hey aspirant,

If I tell you in short then IT(INFORMATION TECHNOLOGY) is careers are more about installing, maintaining, and improving computer systems, operating networks, and databases whereas CSE(COMPUTER SYSTEM ENGINEERING) is about using mathematics to program systems to run more efficiently, including in design and development.

If we talk about technical differences in then-

CS takes a more balanced approach between theory and application while IT focuses more on application

CS offers you an opportunity to learn variety of topics related to computers. IT offers you an opportunity to discovers innovative uses of those fundamental concepts.

CS generally require a decent background in math while use of math in IT is limited to data analysis / processing / statistics, etc

You may call IT as one of the sub-divisions of CS, however there are certain things that are unique to IT like integrated programming, system administrations, maintenance, etc

Hope it helps.

Good luck.