There isn't really a single way to define a country. For background, I would recommend this video from the Map Men: https://www.youtube.com/watch?v=3nB688xBYdY

But following their conclusion: the thing that makes you a country is being recognized as one by other countries. Most of the world recognizes Palestine as a country (including 157 UN member states). Here is a map where the green countries recognize Palestine, and grey do not: https://upload.wikimedia.org/wikipedia/commons/0/08/Palestin...

What are the Palestinians then?

Many countries disagree with that. However, virtually everyone agree that it is not Israeli territory.

oh nice, you are making us all sob with those tough words