Thanks for the link. It would be an update as current version is 7.1.7.
"An update is a new distribution image that contains cumulative fixes and enhancements to the product since Pega 7.1.0; it is not a full product release. In contrast, upgrades are full product releases. If you need to move from any version prior to Pega 7.1.0, you must upgrade. To move from any Pega 7.1.x version to the most current release, run the update."