General rules (please read carefully as it can be confusing):
1) One psn account can reside on 2 PS4s. 1 of the PS4 is activated as the "Primary PS4" for that account. The other 1 let's just call it secondary PS4.
On those 2 PS4s, apart from this particular account, there can also be other accounts residing. (Note that the same PS4 can be activated as "primary ps4" for multiple accounts, all at the same time. Every account on a PS4 is equal, there is no such thing as 'primary account' for a PS4.)
2) On the "Primary PS4" for an account, digital items owned by that account (games, DLCs, PS+ online access, themes) can be used by other accounts on that PS4. (Some games and DLCs may be locked to the account or region; avatars are always locked to the account.)
3) On the secondary PS4 for an account, digital items owned by that account can only be used by that account, they are not shared.
So with these rules in mind, let's say you have a home PS4 and office PS4, both with your account.
If you activate the home PS4 as its primary, then on the office PS4 everyone must use your account to play games that you own. Your colleagues cannot use their own accounts to play your games (cos not shared on secondary ps4). (Letting other people use your account also means that if your account has any wallet balance or payment method stored they can make purchases with it, though the purchased items go back to your account.)
If you activate the office PS4 as its primary, then on the office ps4 other accounts can play your games; but on your home PS4 you can only use that account of yours, your wife/kids for example cannot use their own accounts.
