Questions of a fifteen year old homeschooled Christian virgin

What’s the difference between cumming and orgasming (is that even a word? Who knows)? I hear people say stuff like I came and it got everywhere but I’m I don’t hear the same thing when discussing orgasms. How will you know when one of these things happens? Is it just that little burst of pleasure or is it something else? I’m probably gonna get SLAMMED in the comments so I apologize for my naivety.