That is correct - the first number is always a "1". As to the 2nd number - the examples I'm going to refer to here are very simple (and not entirely accurate) - but are used to explain the difference in the last number of our scale:
Lets imagine you are flying up in a hot air balloon and you take a photo of a forest from 200 feet directly above it. The amount of detail in that photo shows individual branches, leaves, and perhaps even the ground beneath. That scale is 1:200 -and would be called a LOCAL map.
Now, take that same photo from 5000 feet up. While you can see that same forest, you can't make out individual branches, leaves etc. You can see MORE of the forest, but small details tend to fade away. That scale would be 1:5000 and would be called a REGIONAL map.
Go 30,000 feet up and take that same photo again. Now that same forest is a small patch, and details of it specifically blend in with the surrounding countryside. The scale would be 1:30,000 and would be called a CONTINENT map.
Does that help?