I was reading Google's Android documentation and came across with this sentence. Link: https://developer.android.com/guide/components/services
There is written like this: "These are the three different types of services:" and it counts the services. To me that "the" article before "three" sounded awkward and I have never seen that usage before. Is it correct? If so, what made them put the article in that sentence?
What is the difference between "These are three different types of services:" with "These are the three different types of services:"?