Every platform names its audience differently — subscribers (YouTube, Snapchat), followers (TikTok, Instagram, X), members (Telegram, Discord) — and the same word can mean free on one platform and paid on another.
The trap word: subscriber
A YouTube subscriber pays nothing; a Twitch subscriber pays monthly (the free action there is following — see the Twitch guide). YouTube confusingly also has paid channel memberships on top of free subscriptions. Always check what the word costs on that platform before comparing numbers.
Comparing across vocabularies
The honest common denominator is: people who opted into your future content for free. That is the number our platform counters track for each network, whatever the local word is — and each platform page states which metric it shows.