Let’s begin by looking for a known volunteer - Marcus Velásquez.
You don't have to enter the person's complete last name to search. By entering just the first few characters, VSys will find all of the people whose names begin with what you entered. This is especially useful if you're not sure how the name is spelled.
Entering a Date of birth brings up all people who were born on that date, regardless of the name criteria you enter. People who match both the name and date of birth criteria will sort towards the top of the list.
Including a Company finds people who are employees of a company that begins with the values you enter (not a relationship search, this uses the Company field in the Profile editor).
Including a team name brings up teams with that name, and selecting a gender will only show those people who have that gender, or who have none recorded.
Use the Exclude filter to show inactive, archived, deceased or placeholder people. They are excluded by default.
The Short ID is a person's five-character alphanumeric ID which is assigned by VSys. The Short ID is not necessarily unique, but it is close, and makes a great way of finding people quickly. (You can see a person's Short ID on the top right of their Personal data panel in the volunteer profile.)