Let's see quickly another object type in Ruby. We don't use much Constants as they are very similar to variables the only difference is that they should stay constants while variables change. The other difference is that we specify them with all capital letters. But there are a couple of corks with them we need to recognize. I created a small screenshot which explains it all.
The first cork is that everything starts with a capital letter is considered as a constant. The second cork is that even though constants supposed to be constants when we change the value of a constant, we get a warning but the value does change.
These things probably will change in future Ruby versions but it's good to keep them in mind.