You need to understand
why the way in which the archaeological record is formed is so important
the basis of some ideas which archaeologists use to interpret archaeological remains
the strengths and weaknesses of some of these ideas.
As humans, we use ideas and models to interpret the world around us. It is impossible to describe something or another person without likening them to something or somebody else. The same is true for archaeology. The goal of archaeology is to explain (not really reconstruct) past behaviour, but archaeologists do not dig up behaviour. They excavate material remains from the past and assume that behaviour and the ideas that motivated behaviour will be reflected in these remains. They then use theories from the present to make sense of the archaeological record. For example, you need theory to interpret a dark circular mark as a posthole or a particular burial as that of a chieftain. This way of thinking, which links material remains to their interpretation as evidence, is known as middle-range theory.
This is the raw data for archaeology. The physical remains of past activities include features, artefacts and ecofacts (including human remains). The archaeological record comprises these remains in the contexts in which they come down to us.
Debates between archaeologists often stem from differences in their assumptions about how the archaeological record was created and how one should interpret it. On degree-level programmes you will encounter a variety of theories of archaeological knowledge. Below