It is common for learners of English to confuse 'there', 'their' and 'they're' especially since they all have the same sound when being pronounced. Here is an explanation of each one:
'There' has the opposite meaning of 'here'. It is used to mean 'not a place close to' the speaker.
Have you seen mu glasses?
Yes, over 'there', on the table.
I'm driving to work. I'll call you when I get 'there'.