u/liamsdeath

I know they both mean something like only, but what's the difference

I'm somewhat of a begginer at learning Russian, and I know that most of the time any noun ending with a vowel is feminine, and any noun ending in a constanent is masculine (with the exception of gender neutral nouns, which I still dont understand in the slightest). But I've seen nouns that end with ь be described with a feminine adjective ending in ая. I guess I never really considered what ь actually is, I mean it makes no sound so I feel like it can't be put in either category, but is it a vowel? This language is so confusing, I hope what I said made sense and I hope I put the correct tag