Bottom bar of the menu

The bar under the menu holds what you change often, from left to right:

ButtonWhat it does
Mic On / Mic OffMutes or unmutes your microphone.
SoundOpens the three volumes: World, Voices, Menu. See Sound volumes.
Standing / SeatedSeated mode: your avatar stands while you sit.
RespawnTakes you back to the spawn point of the world, after asking.
PhotoOpens Camera and Gallery.
Do not disturbLit up while it is on: no invites, no invite requests, no notification sounds. See Do not disturb.
MessagesOpens your private messages; the number is what you have not read.
NotificationsOpens your notifications; the number is what you have not seen.

Sound

Sound opens three sliders above the bar. Move them with the ray; click anywhere else to close them.

Respawn

Respawn asks "Respawn?" first. Choose Respawn to go back to the spawn point of this world, or Cancel to stay where you are. The menu closes once you have moved. With keyboard and mouse, Shift+R opens the menu on the same question.

Respawn also gives you back your own moves: if the world held you still, changed your speed or your gravity, or sat you down, that is undone (see You can always leave).

Photo

Photo opens two choices: Camera takes the camera out (Put the camera away while it is out), Gallery shows your photos (see Gallery).