Answer
Cold Observables start producing values only when subscribed. Each subscriber gets its own execution (e.g., HTTP calls).
Hot Observables emit values regardless of subscriptions. Subscribers join an active stream (e.g., events, websockets).
Quick Answer
Cold observable: each subscriber creates a new independent execution. HTTP calls are cold - every subscribe makes a new request. Hot observable: single execution, all subscribers share it. Mouse events are hot - event happens regardless of subscribers. The distinction matters for avoiding duplicate HTTP calls: use shareReplay(1) to make a cold Observable hot and cache the result.
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SugharaIQ Editorial Team
Verified Answer
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Source: SugharaIQ