Because some series every episode, there’s an individual story. Is it like this?
I personally love Criminal Minds, I hate the lack of chronological order on A&E for it, you can watch every episode in order here:
Most episodes are plotted individually but conflicts within the team are revealed in a long-term sentence of every episode, as previous conflicts within the group are shown in later episodes as well.
It’s quite the show.
Cucirca Criminal Minds
There are some like that, but for the most part you should be able to watch a random episode and fully understand it! I’ve done it plenty of times!