We use the present simple to talk about actions we see as long term or permanent. It is a very common and very important tense.
Here, we are talking about regular actions or events.
- They drive to the office every day.
- She doesn't come here very often.
Here, we are talking about facts.
- Water freezes at 0° C or 32° F.
- The Thames flows through London.
Here, we are talking about future facts, usually found in a timetable or a chart.
- Christmas Day falls on a Monday this year.
- The plane leaves at 5.00 tomorrow morning.
Here, we are talking about our thoughts and feelings at the time of speaking. Although these feelings can be short-term, we use the present simple and not the present continuous.
- They don't ever agree with us.
- I think you are right.