The soft sign is a little curly line that looks like a backward "h." It's a special letter in the Russian alphabet that helps change the sound of the words you're reading or saying.
Basically, when you see a soft sign after a letter, it means you have to make the sound of that letter softer. It's kind of like when you talk in a really quiet voice so you don't wake up your baby brother or sister.
For example, the letter "T" sounds hard and sharp, like a punch. But when you add a soft sign after it (making it "Ть"), it becomes softer and gentler, like a little tap.
The soft sign is important because it can change the meaning of words. For example, the word "боль" means "pain," but if you add a soft sign after the "л" (making it "больь"), it means "a large amount" instead.
So, to sum it up, the soft sign is a special letter in the Russian alphabet that helps change the sound and meaning of words by making them softer and gentler.