Super PACs are unlike traditional PACs in that they may raise unlimited amounts from individuals, corporations, unions, and other groups to spend on, for example, ads overtly advocating for or against political candidates. However, they are not allowed to either coordinate with or contribute directly to candidate campaigns or political parties.
There are limits to what an individual can donate to a campaign and a PAC. There are no limits to donating to a Super PAC.
https://www.fec.gov/help-candidates-and-committees/taking-receipts-pac/contribution-limits-nonconnected-pacs/
https://www.fec.gov/help-candidates-and-committees/taking-receipts-pac/contributions-to-super-pacs-and-hybrid-pacs/
https://en.wikipedia.org/wiki/Political_action_committee#Super_PACs