A subjective experience refers to the emotional and cognitive impact of a human experience as opposed to an objective experience which are the actual events of the experience. While something objective is tangible and can be experienced by others subjective experiences are produced by the individual mind. While quite real to the person experiencing a subjective experience and often profound it cannot be objectively or empirically measured by others.
For instance, we are all having a subjective experience whenever we are experiencing pain. Although we as an individual can identify and feel the specific components of the pain no one else can fully measure or feel our own subjective experience of pain.