É is "is". Está is also "is", but it's used as a state. For example, it is cold in Brazil: No Brasil está frio. In this case frio is a state, it's not always cold, but now, at this moment, it's cold in Brazil. Ice cream is cold: "Sorvete é frio" this means that it's always cold, it's not just a state, it IS cold. If you say "O sorvete está quente", (the ice cream is cold) this indicates a state, because the ice cream is not always cold, but now it is. Tá is just short for está, and used in colloquial speech. DO NOT use tá in formal written text, it's like using "u" instead of "you".

estar= state. it's used to indicate temporary states and locations. Eu estou feliz agora - I'm happy now A escola está entre o hospital e o posto de gasolina - The school is between the hospital and gas station. ser = essence. it's used to classify and identify permanent or lasting characteristics. Eu sou rico - I'm rich Maria é bonita e esperta - Maria is pretty and smart.

"Esta" means "this"... And" Aquele ou aquela" means "that"... Right?

tá is reduction from está , but it's used only in speak. don't use in write.

If you referred on when they use them in short answers: é: it's like: "yes, right, it is": tá it's the slang form of "está", you can use it as ok... tá bom (it's ok)