Definition
Consent, in the GDPR sense, is a freely given, specific, informed, and unambiguous agreement to have your personal data processed for a stated purpose. It is one of six lawful bases for processing and the most common for marketing forms. Valid consent means: separate opt-in for each purpose (newsletter vs product updates are different), no pre-ticked boxes, plain language, and the ability to withdraw at any time.
Regulators have been clear that "by continuing to use this site, you agree to our cookies" is not valid consent. The bar is active affirmation - clicking a checkbox, hitting a consent button. And you have to prove it later: store who consented, when, what text they saw, and what version of your policy was in effect.
How SheetLinkWP relates to Consent (data)
SheetLink Forms supports a consent checkbox on every form and captures the exact consent text, timestamp, and policy version as dedicated columns in your Google Sheet. If a user later requests deletion, that audit trail is how you prove (or disprove) that you had permission to hold their data. The checkbox is a simple field in your form plugin of choice - SheetLink just adds the sheet-writing plumbing.