"Person" refers to who is the subject of your sentences: yourself or a group you belong to, a person or group you are addressing directly, or a person or group you are simply describing. The different persons are as follows:
First (the self): I, me, my, mine, we, us, our, ours
Second (the person spoken to): you, your, yours
Third (the person spoken about): he, she, it, they, and many other words that you can see in the link below.
Generally, in academic writing, you want to stay in third person for these reasons:
first person can be seen as biased or too focused on one opinion, and
second person can be distracting because it can force associations on the reader that may not be true or relevant.