Can you explain the concept of Cold Observable and how it differs from Hot Observable?

Cold Observable is a data stream that starts emitting values only after a subscriber subscribes to it. Each subscriber receives the full set of data from the beginning.

Hot Observable is a stream that emits data regardless of whether there are subscribers. Subscribers only receive data emitted after they subscribe.

Example:

• Cold Observable is like a movie recording: every viewer starts watching from the beginning.
• Hot Observable is like a live broadcast: if you join later, you'll miss the beginning.

In RxSwift or RxJava, a cold Observable is created, for example, using Observable.create, while a hot Observable is created using Subject or PublishSubject.