Manage Record Types - In this section, you can rename system records name which reflects changes in the entire interface 365.
Here, a list is mentioned of all the existing records in the Interface 365. One can update the name of any record type and while updating it gives an option to update the name as singular or in the plural. Although after submitting to update it will ask you to please select REFRESH to sync your record name, as once you update, changes will reflect across the entire Interface 365.
Here you can see how it works for leads:
1. Here, you select the record name "Lead."
2. In below screenshot, you can see how it will give you an option to edit the record name as singular and plural whenever you select an option for the edit record name.
3. Once you submit the update, it will ask to REFRESH to make changes in the entire Interface 365.
4. Now, in below screenshot, you can see how changes made on it.
NOTE- This same process will going to happen for every record type.