Safe Checks
Today's lesson is all about safe checks. When you check your opponent's king, it needs to be 100% safe so you can make sure your piece doesn't get captured. Here's an example:
I could move my queen to h5 and check - with the price of the queen getting captured by the knight. If the opponent doesn't see this - a risk I didn't want to take - the king has to move. Though if we remember the ideal way to get out of check, blocking or taking rather than moving, the knight will take my queen and have a good shot at checkmate.
Now I could use my posted knight on d5 and take the black knight... making the pawn take the knight and allowing my queen to make a clean and safe check.

Clean checks are the best kind.
White takes the checkmate in this game. The point of this lesson is that a safe check is a good check - potentially losing your best pieces is never fun, right? Keeping your eyes open to all dangers keeps you safe. I hope this helps. See you next time!