Slinky waves refer to the waves represented by a spring/ slinky. It can be used to represent both longitudinal and transverse. Refer attached images below. Similarly, the seismic waves are of two types - longitudinal waves (P-type) and transverse waves (S-type). During an earthquake, the rupturing process causes the seismic waves to transfer energy without moving any material from one place to another. the P-type waves are faster than the S-types waves.
