So a lot of the time with math names like "imaginary" just leads to confusion. In general these are numbers we can use in math to calculate things, but that you cannot physically hold in your hand.

Forget imaginary and just think of negative. You cannot hold in your hands "negative 5 apples". You can however represent it with a note and poof you now have credit and debt, all because you are considering a number that cannot physically exist (negative of something). Imaginary numbers are just another leap in this sense going even deeper into math.

The point ultimately is that they let you calculate things that might otherwise be impossible to calculate by filling in gaps.