A cookie banner, also called a GDPR cookie notice, informs users that your site runs cookies and gives them the option to access more details and either grant or reject consent.
It has to be shown on the user’s first visit, and you have to keep track of and save consent settings for each user for up to 12 months from the last site visit.
Having an accurate cookie banner, cookie policy and blocking cookies before consent are all requirements under the ePrivacy (Cookie Law) and GDPR.