<p>The search for extraterrestrial life is of increasing interest throughout the world. Various organic and inorganic materials, fossils, patterns, objects, and substances have been identified as “biosignatures,” thus providing a hint to the existence of life on planets other than our Earth. These indirect shreds of evidence can be preserved and stored at different micro- to macroscopic levels. Identifying a biosignature helps to define an exoplanet as habitable. This review highlights different types of biosignatures that are known to be “potential biomarkers,” their significance, and their detection techniques. It also focuses on how to differentiate a biosignature from an abiosignature molecule and is also useful in understanding certain terminologies such as <i>abiosignature molecule</i>, <i>ambiguous biosignature</i>, and <i>agnostic biosignature</i>. Furthermore, this review provides insights into future directions of utilizing different techniques for the precise and accurate identification of biosignatures extraterrestrially.</p>