Viewer levels are earned by viewing and interacting with streams.  Sending gifts is the fastest way to earn XP towards your next viewer level.  Viewer levels are represented by a number, and can be seen in the ring around your profile photo while chatting in a stream.

Viewer levels unlock exclusive gifts you can send to streamers by accessing the “Exclusives” gift menu.

Streamer levels are earned by streaming and receiving gifts from viewers.  Receiving gifts is the fastest way to earn SP towards your next streamer level.  Streamer levels are represented by a precious metal or gem, and a roman numeral (example: Silver IV)

Streamer levels unlock streamer perks such as gestures, masks, backgrounds, bonus rates for Diamond to Point conversions, and access to streamer subscriptions.

Your current viewer and streamer levels can be viewed in your Streamer Tools menu which you can access by tapping the wrench icon on the Live home page.  To earn the most XP or SP towards new levels, check out the awesome XP and SP boost items you can earn via challenges.