There is an adverb that means in or at that place or position. It can also be used to introduce a subject or to emphasize a point. For example:

• She is waiting for him over there.
• There are two cups on the table.
• There is no need to worry.

Their is a possessive pronoun that shows ownership or possession. It is used to indicate that something belongs to or is associated with them. For example:

• They left their books on the table.
• Their car is in the driveway.

They’re is a contraction of “they are”. It is used to mean “they are” in a shorter, more informal way. For example:

• They’re going to the store.
• They’re not coming to the party.

In summary, there is an adverb that means in or at that place or position, their is a possessive pronoun that shows ownership or possession, and they’re is a contraction of “they are”.