Inlay hints are special markers that appear in the editor and provide you with additional information about your code, like the names of the parameters that a called method expects. Other types of hints inform you about annotations, method parameters, usages, and so on (depending on the language).
In inlay hints settings you can configure which types of information you want to get in hints.
Change inlay hints appearance
In the Settings/Preferences dialog (Ctrl+Alt+S), go to , then select Inline hints.
Select the inlay hint type and state, and configure the font, color, and effects as required.