Every time someone criticises the Israeli State or Zionism ideology, there is always someone who comments shouting about Anti-Semitism and how anyone who questions, criticises or condemns Israel's behaviour is Anti-Semitic. And it's really annoying because it's not true.
The definition of Anti-Semitism is "Prejudice or Hostility towards Jewish people".
Anti-Zionism in the context of the ongoing conflict between Israel and Palestine is being opposed to Israel's decades long oppression, genocide and apartheid of Palestinians. Including but not limited to leaving people stateless, giving Palestinians less rights than Israelis and creating the open air prison that is Gaza, depriving the people there of water, electricity and food, and bombing relentlessly while not giving anyone a way to escape.
Plenty of Jewish people practice their faith, but are anti Zionist and condemn what the Israeli government are doing.
And plenty of Zionists are Anti-Semites, but support the behaviour of the Israeli government (including a decent chunk of British MPs according to Google)
Disclaimer before anyone jumps on me: I absolutely condemn and despise Hamas and their actions. I've not mentioned them as they're not relevant to my point.