Usernames can have multiple different ways of appearance across Discord. Nicknames, Usernames, and Tags are the most prominent and you can choose to select those as an Identification setting.
Chat Identification
To change your user Identification setting, you can use the /manage settings Identification command.
Tag setting
This setting is the only setting that doesn't prevent users from seeing user tags. These tags allow mostly for pinging across servers by using TagPings
MessageLogs allows another way for moderators to access User IDs for moderation
Setting Identification as tag will make your users' chat display names look like this
Example of Tag Identification
Username setting
Setting Identification as username will make your users' chat display names look like this
Example of Username Identification
Nickname setting
Setting Identification as username will make your users' chat display names the originating guild's set nickname for that user.
Example of Nickname Identification
Anonymous setting
This setting will hide the message sender's identity without preventing differentiation. Message display names will look like this
Example of Anonymous Identification
The profile picture will be replaced with the webhook's profile picture. This could be a legacy image of Connections Bot.