Archaeology doesn't just concentrate on the periods before written history, (prehistory), it can also reinforce the written history that we know or even contradict the history that we think we know or knew.

Archaeology isn't just about digging holes and bringing up bones covered in gold and treasure. The subject of archaeology is immensely complex  and incorporates a whole variety of skills and technologies. Field Archaeology with a trowel in your hand is only one small part of the process. Legislation and historical documents may need to be checked, geophysics may need to be completed, drawing of finds and accurate recording needs to be carried out, analysis of some finds may need to be carried out including carbon dating or soil sample analysis to name but a few of the many processes that can all come together under the umbrella of archaeology. 

There are two very over used phrases that you will hear concerning archaeology, but despite being clichéd they are well worth remembering:

"Archaeology is rubbish" and "Absence of evidence isn't evidence of absence"

Search the subjects on the menu to go through some of the different aspects of archaeology. Obviously the subject is exhaustive so this website only gives an overview and will not cover all of the subject.