Translation:That is a tree.
Yes. 이에요/예요 are used for stating and questioning a noun. 이에요 is used for stating a noun ends with consonant [i.e: 물이에요 (It's water)] and 예요 is used for stating a noun ends with vowel as in "나무예요". Both 이에요/예요 can be used to question something by raising the tone at the end of the sentence like 뭐예요? (What's that/this/it?) or 물이에요? (Is this/that/it water?)
"그것" in this case means "that". It means that something is a bit away but still close to you in proximity.
"저것" also means 'that", but it means that the thing is far away from you.