Official guidance · EDPB Guidelines 2/2023, para. 47
Tracking pixel (web beacon)
In plain English
A link to a resource, usually an image, embedded in a web page or email to make the device contact the pixel's host. The EDPB treats collecting identifiers this way as covered by the ePrivacy rule on device access.
The official text
A tracking pixel is a hyperlink to a resource, usually an image file, embedded into a piece of content like a website or an email. This pixel usually fulfils no purpose related to the requested content itself; its sole purpose is to automatically establish a communication by the client to the host of the pixel, which would otherwise not have occurred.
it can be considered that the collection of identifiers provided through such tracking mechanisms constitutes a ‘gaining of access’ in the meaning of Article 5(3) ePD, thus it applies to that step as well.
Related
The official text is quoted word for word from the English version of the source named under it; only the version published in the Official Journal of the EU is legally binding. The plain-English line is Fino’s own summary, not legal advice.