There are differences in meaning in some contexts, but in a general context they are the same. Basically גבר means man while איש is the masculine form for person (i.e. man, but this subtlety is the basis for the contextual differences). The difference I think is most important is in the plural form:
- גברים = men
- אנשים = people
In the context of this sentence there is also a subtle difference:
- אתה איש = You are a person (masculine). This does not emphasize the gener – and you probably won't say this in real life, it sounds strange.
- אתה גבר = You are a man – often used to emphasize manliness, but can also be sarcastic, i.e. "some man you are".
They are pretty much the same, גבר stresses the gender more but it's not as if איש is gender unspecified.
I have a similar question. I had to translate "גבר" into English, but the male audio voice pronounced it "גבל". Are these two forms equivalent?
Not sure I understand the questions here. גבל is not a word for man in Hebrew and it is not accepted here. The audio pronunciation says גבר, that's how we pronounce it.