How can the number of (Offensive) Possessions differ between two teams in the same game?

[WestGOAT]

I was reading the following:https://squared2020.com/2017/11/25/offensive-and-defensive-ratings/

Snippet:

Cleveland 102, Boston 99
On opening night, the Cleveland Cavaliers obtained 98 offensive possessions to Boston’s 95 possessions.

Are these extra possessions resulting from plays at the end of a quarter? Basically teams that successfully pulled off a "2 for 1" play? Would 1 be the max difference in offensive possessions in a quarter? So it's expected to be 4 at the most in a regular 48-min game?

[Squared2020]

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