1. Fingerprint Recognition: A fingerprint is made up of ridges and grooves. Uniqueness is determined by the ridges, the grooves, the points of minutiae. Fingerprinting is one of the oldest and most popular recognition techniques. Each individual has unique finger patterns, even twins have different patterns of rings and grooves. Fingerprint matching techniques are of three types:a. Minutiae-based techniques: In these minutiae, points are identified and then mapped to their relative position on the finger. There are some difficulties, for example if the image is of low quality it is difficult to find the minutiae points correctly, also it considers the local position of ridges and sulci not global [4].b. Correlation-based method: Uses richer grayscale information. It overcomes the problems of the above method, it can work with bad quality data. But it has some problems like localization of points.c. Template-based (image-based) matching: Template-based algorithms compare basic fingerprint patterns (arc, spiral, and ring) between a stored template and a candidate fingerprint. Advantages: • It is the most developed method so far • Relatively cheap • Even twins have unique and highly secure fingerprint patterns. • Small size of the pattern, so matching is also fast Problems: • Systems can be fooled by using artificial fingers such as fingers made of wax• Cuts and scars can create obstacles to recognitionApplications:• Verifying the authenticity of the driving license and checking the validity of the license • Law enforcement • Border control/issuing visas2. Facial recognition: Facial recognition is based on both the shape and position of the eyes, eyebrows, nose, lips and chin. It is a non-invasive method and also very popular. Facial recognition is done in two ways... in the middle of the card... as in the case of cataracts[12] [13]Applications:• used by several government agencies including FBI, CIA and NASA• Used for medical diagnostic applications6 . DNA Recognition: Human DNA is the genetic material that can be found in every single cell of an individual's body. There are numerous sources from which DNA patterns can be collected such as blood, saliva, nails, hair and others. The collected DNA samples are fragmented into shorter fragments organized by size and then compared. However, this technology is not automated and needs to be perfected. Advantages: • It is a very unique feature • Performance is high • Its universality is very high Problems: • More information, therefore privacy issues • More storage space is required • Non-automatic technique Applications: • In forensics • Used in courts and the law to prove guilt or innocence• Physical and network security