Parser

Hi,
I would like to know in simple terms "what is a parser?". Can anyone please tell me what it is and what it does?
Thank you,
Derek

[charlass]

"parsing" means to read data, which are stored in a specified format, and to present them with a (for a programmer) better usable interface.

You know the algorithm how to get the data, but it is difficult to implement (read until you find the first "", ... puuh).
With an existing parser, you give it the document, it has a callback-interface like "onBeginNode( name="myRoot")". Much easier, isn't it?