A new addition to the updated exam guide Salesforce released on June 23, 2021 is the Setup Audit Trail.
The Setup Audit Trail is available in Setup via View Setup Audit Trail. There you'll find the 20 most recent changes to your Salesforce org. You can also download the past 6 months of audit line items that are in the Setup Audit Trail.
Updated Exam Guide - https://trailhead.salesforce.com/help?article=Salesforce-Certified-Administrator-Exam-Guide#Exam-outline
Monitor Setup Changes with Setup Audit Trail - https://help.salesforce.com/articleView?id=sf.admin_monitorsetup.htm&type=5