A “sample” is a piece of a pre-existing recording. A sample can be taken from any part of the pre-existing recording such as the melody, beat, vocals, speech, or rhythm, or it can be every aspect of a portion of the recording.
The practice of sampling is when a musician includes a sample of a pre-existing recording created by somebody else in their own recording. Samples are often manipulated in various different ways before they are added to another’s work, or sometimes the sample is included as it was originally recorded.
Any time you use a sample of another person’s pre-existing recording, you should seek permission from the copyright owners of that portion of the musical work and sound recording!
Otherwise, use of the sample may still be violating the exclusive rights of the copyright owners.