You think you're going to get a better answer by asking that here rather than by reading the Wikipedia article or a media company's summary of what Hamas is?!

As neutrally as possible:

Hamas is an organization in the area of historical Palestine. It has been governing the Gaza Strip, a small piece of land between Israel, Egypt and the Mediterranean Sea, since 2007.

Ever since then, Israel has been blockading the Gaza Strip. Every few years, eg. in 2014 and 2021 and now again, Hamas fires rockets at Israel or otherwise attacks it, to which Israel responds with airstrikes.

Palestinian narrative: Israel is a settler colonial state that has taken away Palestinian land and is imprisoning Gazans in Gaza. Fighting against that is legitimate resistance against oppression. Israel's goal is ethnic cleansing of the Palestinians.

Israeli narrative: Israel is a safe haven for the historically oppressed Jewish people. Arabs have plenty of other countries for themselves. The aim of Hamas is to eliminate the Jewish state and maybe even the Jewish people. Israel is doing its best to avoid civilian casualties in its airstrikes against Gaza.

The actual truth: There is no such thing as the actual truth. There is a reason why this is the most difficult conflict in the world.

inb4 people with strong opinions on both sides tell me their opinion is obviously right and the above is nowhere near neutral