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?

Historically, Palestine has never been a country. The Romans captured Judea, and later expelled the Jews and renamed the province Syria Palaestina (after previous enemies of the Jews). After the Romans, many other empires held the land: the Arabs, Mamluks, Turks, British. But at no point was it a country. Even when the Egyptians and Jordanians captured Gaza and the West Bank, they didn't give independence to Palestine. Israel captured Gaza/West Bank. They gave full control to Gaza in 2005. So you could say Gaza is a country now.

Yes, that's the standard text, I know. (Just ignoring the arab movement since the 1880s to make it a country and the British promise to help with that).

But that wasn't my question. If Palestine isn't a country, then what are the Palestinians?

There are official old coins, newspapers, etc. with Palestine written on them. It has long been an entity.

Here’s a bit of history lesson: https://en.wikipedia.org/wiki/Mandatory_Palestine

TL;DR has nothing to do with Palestine of today

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