* Colleges typically offer undergraduate (Bachelor's) degrees. They may offer some limited graduate programs (Master's or Doctorate), but this is less common than at universities. They tend to be smaller and more focused on undergraduate teaching.
* Universities typically offer a wider range of programs, including undergraduate, graduate (Master's and Doctorate), and professional degrees (like law, medicine, dentistry). They also usually have a strong emphasis on research alongside teaching. They tend to be larger and more complex institutions.
* Colleges often are part of a larger university system. A state university system might include several colleges that grant undergraduate degrees, but the overall entity is considered a university because it houses graduate programs and research centers.
In short: Think of a university as a larger, more comprehensive institution that encompasses a variety of colleges and schools, offering a broad spectrum of educational programs and research opportunities. A college is often a smaller, more focused institution primarily dedicated to undergraduate education. However, many colleges are now offering graduate degrees and conducting research, blurring the lines significantly.
The distinction is more of a historical and organizational one than a rigid rule. Many institutions that call themselves "colleges" are effectively universities in scope and offerings, and vice versa. The name alone isn't always a reliable indicator of the institution's structure or programs.