From a legal point of view, a deposition definition is the testimony of one or both parties, eyewitnesses or anyone else pertinent to the case at hand answering questions, under oath, being either recorded by a device, in the presence of a court reporter or both.
In the deposition definition the deposition occurs before the trial and the testimonies collected can be used as evidence in the court. Discoveries are used to help find more information if not outright forfeit or acquittal causes from evidence discovered at a deposition.
Other documents, photos and other attachments can be requested at a deposition. These documents will be marked and numbered and added as exhibits for the deposition. All parties will be given copies of the exhibits.
When a deposition is finished, all parties will concur meaning that they all agree that all the documents and exhibits are true and correct. The agreement that all the documents and exhibits for a deposition by two opposing attorneys are seen to be true and correct is the text book example for a concur definition . The two attorneys agree, shake on it, cut a deal that all documents are seen as to be true and correct, and generally make a lot of money. They, in short, concur.
The deposition definition is much more complex and complicated than the one mentioned here, however, this definition should give you enough a general idea as to what deposition means.