"Subliminal" refers to stimuli that are below the threshold of conscious perception. This means that individuals are not aware of these messages, yet they can still influence thoughts, feelings, or behaviors. Subliminal messages can be visual or auditory, often embedded in media like advertisements or music. The concept gained popularity in the mid-20th century, particularly after the James Vicary experiment, which claimed that flashing messages could increase sales. However, the effectiveness of subliminal messaging remains debated among psychologists and marketers, with many studies showing mixed results regarding its impact on consumer behavior.