Quality update or Service update in 365 FO LCS

 https://community.dynamics.com/blogs/post/?postid=9ec02826-fedc-4a77-afe4-c9b064efa17e

In Dynamics 365 Finance and Operations (D365 FO) via Lifecycle Services (LCS), there are two main types of updates: Quality Updates and Service Updates.

Quality Updates

• Purpose: These are cumulative roll-up builds that contain fixes for known issues specific to the service update.
• Availability: Quality updates are available for any in-service version¹.
• Content: They include all previous updates and are designed to improve the stability and performance of your current version².

Service Updates

• Purpose: These updates include new features, improvements, and fixes. They are part of the regular update cadence set by Microsoft.
• Cadence: You can configure the update cadence for your production and sandbox environments in LCS. Typically, the sandbox environment is updated seven days before the production environment³.
• Configuration: You can select the week, day, and time slot for the updates to be applied³.