The current Google Account is displayed at the top of the Inbox. If you have more than one account, you can switch accounts to view the messages in each Inbox. Simply tap the Accounts & labels icon at the top left corner to select another account or label to display.
Conversations with new messages are displayed with bold subject lines. To read a message in a conversation, tap its subject line text.
indicates that you were copied on this message.
indicates that this message was sent directly to you.
Tap the letter icon (or contact photo) next to a Gmail message, then you can tap the Archive icon , Read/Unread icon , Move to icon , or the Menu icon (Delete, Change labels, Add star, Mark as important, Mute, Report spam, and Report phishing).
You can also tap the Favorite icon next to a Gmail message to designate it as a favorite message.