Dumb question but pls help

What does bleeding between period mean? Like what’s the process like if that make sense

I google it but it still not making sense to me.

This is what i toook from it....

You spot then it’s heavy then light again then you spot again

My period came in time and ended on time. It was just heavy the first then then regular/light for the rest 6 days. My period lasted 7 days in total