And versus Or

The words "and" and "or" are easy to mix up. Drawing the solutions on the number line keeps them apart. x >= -3 and x < 1 means both conditions hold, so the solutions are the overlap. The overlap is the segment from -3 to 1, with -3 included and 1 excluded. As a chain, it is -3 <= x < 1.

x ≥ -3 and x < 1: the overlap, one segment

x < -3 or x >= 1 means either condition may hold. The solutions are everything outside that segment, which is two rays.

x < -3 or x ≥ 1: two rays

"And" gives fewer solutions, because both conditions must hold. "Or" gives more solutions, because either condition is enough.