Biometrics is a term that encompassed the application of modern statistical methods to the measurements of biological objects. The term biometrics usually refers to automatic technologies for measuring and analyzing biological and physiological characteristics such as fingerprint, eye retina, iris, voice, face, signature, etc. for individual identity. Later Multimodal biometric systems are introduced which are more efficient than uni-modal systems, in which single identification/verification done basis on multiple patterns. To improve the quality and speed of the multimodal systems equally need an improvement in preprocessing techniques too. Towards this issues a no of compression techniques are included as a preprocessing steps in both uni-modal and multimodal biometric systems.