Subs has 3 meanings
This channel's chat has gotten so much better since it switched to subs-only.
|Twitch||Video game streaming website|
|Streamer||Someone who regularly broadcasts on Twitch.tv|
|Raid||To send viewers to another streamer's stream|
|Take my energy||Good luck|
|Fandom||Community of fans|
Most likely, those who refer to subtitles as "subs" are planning to watch a foreign language movie or TV show for which they need subtitles. For example, English-speaking anime enthusiasts often use fan-made subs while watching shows that have not yet been dubbed into English.
Even when an anime has been dubbed into English, English-speaking fans may prefer to watch the show with its Japanese audio and English subs. Fans who feel strongly about this issue may talk about how subs are "always superior" to dubs. (This is a classic weeb discussion point.)
I can't find German subs for Rocko's Modern Life anywhere!
|Weeb||A non-Japanese person obsessed with Japanese pop culture|
|Superfan||An extremely dedicated fan|
|Waifu||A fictional female that a real person has a crush on|
|Husbando||A fictional man that a real person has a crush on|
|MHA||My Hero Academia|
|DBZ||Dragon Ball Z|
On Twitch, subs is short for "subscribers." Viewers can subscribe (or "sub") to a Twitch Affiliate or Partner's channel to provide that streamer with financial support and gain subs-only perks.
Subs subscribe to their favorite streamers' channels, most often at the price of $4.99 per month. In return for their subscription, subs receive unique emotes and badges, access to subs-only chat channels, and other exclusive benefits.
Because streamers earn money for each sub they acquire, they often run promotions that encourage normal viewers to become subs. If you're ready to become a sub, click the Subscribe button that appears below a streamer's stream. If you're not ready to become a sub but still want to show a streamer your support, you can always toss them a dono.
(YouTubers also often refer to their subscribers as subs. They may also refer to the platform's Subscriptions feed as the Subs feed.)