There-sentences

There-sentences are introduced by the word there:

 There  is a man at the door.

  There  is a God after all.

 There  was a phonecall for you.

 There  is no such thing as a popular tax.

There-sentences are chiefly used to introduce new information 
relating to
the existence – or non-existence – of some state of affairs. For this reason they are sometimes called ‘existential’ sentences.

The word there in these constructions should be distinguished from the adverb there, which denotes place:

     There   he is. (cf. He is there.)