こちら / そちら / あちら / どちら こちら / そちら / あちら / どちら + は / が / に / へ こちら / そちら / あちら / どちら + の + [noun]
こちら, そちら and あちら are "this way", "that way" and "over that way", and どちら asks "which way" or "where". They are the polite versions of ここ, そこ, あそこ and どこ, with the same three distances, and you hear them in shops, offices and on the phone.
こちら also points at a person, politely. It is how you introduce someone; このひとこの人 would sound offhand.
どちら also asks "which" when there are two things to choose from. For three or more, the word is どれ.
These go beyond pointing at a place or a direction.
On the phone and in business, そちら stands for the person you are talking to and the people with them, and こちら for you and yours.