You may wish to sign out of PlayStation Network if you use a shared PlayStation system. This may be because a younger person uses the system and you do not want them to have access to your age restricted content and/or because you want to ensure there are no transactions on your Sony Entertainment Network account that you are not aware of.
Please note that if you sign-out of your local user account (step 2) without signing out of PlayStation Network (step 1) your local user account will automatically sign-in to PlayStation Networkwhen it is selected. This means that if another user logs into your local user account they can access PSN and PlayStation Store through your account.
If you have 2-Step Verification active on your account, you need to complete extra account verification to sign in. Find out more about 2-Step Verification.