First-party Cookies are created by a visited website a visitor entered directly. Using first-party cookies means it’s your domain collecting data. This translates into greater control and full ownership of data. In other words, you can handle the data responsibly and safeguard it as best as possible.
First-part cookies have a longer lifespan. Users can delete all cookies on their devices, but first-party cookies won’t be blocked by cookie blockers such as private browsers or ad blockers.
More about first-party cookie and data on the Piwik PRO blog:
First-party vs third-party cookies: why first-party is the way to go
Check out our free Online Cookie Scanner: https://piwik.pro/cookie-scanner/