Qualia are the subjective, individual experiences of perception and sensation. They refer to how we personally experience things, such as the redness of a rose or the taste of chocolate. Each person's qualia can differ, even when they are exposed to the same stimuli, making it a key topic in the philosophy of mind and consciousness studies. Philosophers like David Chalmers have explored qualia to understand the nature of consciousness and the mind-body problem. The debate often centers around whether qualia can be fully explained by physical processes in the brain or if they represent something more elusive and intrinsic to our experiences.