In simple terms, a honeypot is a token that has blocked its sales. You can buy, but you can’t sell, so basically the money you invested is lost.
Other kind of honeypots are soft and uses taxes as a method to discourage and block sales. Or simply take massive profit from every sale to the contract beneficiaries, at the expense of regular holders.
Also, a contract that at some moment was NOT a honeypot, can become one later!
Read more about here!
Your best bet is to use online analysis tools. Pages like https://dextools.io give some security scoring to the tokens, but you can always do the analysis yourself!
We test the contract 0x79967f3e47f6f9198d81f9194f60288d3faa1333. This contract was promoted recently by some careless influencers in Twitter!
Clearly a soft honeypot.