Sports Talk

Could someone explain cricket to me as if I were a beginner?

Since retiring I have more time for sport, and I would like to understand cricket. Many of the members here from India and the UK talk about it with such passion, and I feel I am missing something.

I have tried watching a few times. I understand the bowler throws and the batsman hits, but I do not understand why some matches finish in one evening and others take five days, and why sometimes nobody seems to be in a hurry.

If anyone can recommend which format a beginner should start with, I would be very grateful. Please be patient with an old pharmacist.