Literally anything you can think of. Everything you use was designed by an engineer. There are many different types of engineers depending on your interest. Computer engineers build faster and faster computer like IBM's Watson as well as software engineers that create the software that enabled Watson to beat a chess master. Civil engineers design and build road and bridges etc. etc.
To add to the awesome answer already provided, I suggest that you think of how an engineer impacts all facets of life by looking at both the "soft" and "hard" concepts of engineering. Specifically you have software engineers who, in addition to other tasks, write code that causes expected results...think about writing code that causes a robotic arm to move in a certain way to apply precision in a surgery or lifting heavy items off of a shelf. There is also the "hard" concepts of engineering like as mentioned, a mechanical or electrical or civil engineer. Think about that robotic arm...how light or heavy it is...it's size depending on how and where it will be used or the ability to replicate that arm where or when it is needed.
I share a very, very, very small example of the spaces, "soft" and "hard", where engineers have and continue to play a major role in designing, manufacturing, building and operating important entities in our spaces and in so doing, their work continues to improve lives everyday.
Hope you find this answer helpful and best of luck to you!