Opt-out means that the Data processing is active by default and the user can object subsequently must be given. In contrast to opt-in, consent is given here Not activebut is assumed - until the user explicitly deactivates it.
In the EU, the opt-out model is available for many forms of Tracking or personalised advertising no longer permittedas the GDPR in most cases requires a active consent (Opt-in) required.
However, there are still areas of application (e.g. in the USA or for certain technical functions) where an opt-out is possible or sufficient - for example via the "Deactivate cookies" link or settings in Consent Management.
Important: Opting out must be just as easy as opting in - and must not be hidden or made more difficult.