Forensic Science is any aspect of science as it relates to the law. Any area of science could be called into question in a court of law, but forensic science most often relates to the following disciplines:
Personal Identification.
The name is self-explanatory. This involves how an individual can be identified to the exclusion, or at least to the smallest possible percentage of the population. Includes fingerprints, dna analysis, dental analysis (odontology), and a number of other subdisciplines.
Firearms and Toolmark Identification.
Firearms examination involves the identifying characteristics between firearm and projectile, projectile and target. Typically, this includes matching bullets to the gun that fired them. Toolmark identification involves the identifying characteristics between tools, such as a pry bar, and the object on which it is used, such as a door frame. Also included in the category are explosives and imprint evidence.
Forensic Psychiatry and Profiling.
The first category involves mental illness and disorder, what creates mental illness and disorder, and its diagnosis and treatment. The other category, profiling, is when an investigator examines certain crime scenes to come up with a personality profile of the offender.
Questioned Document Examination.
This discipline involves all special relationships that may exist between document and inscription and how it relates to a person or sequence of events. This includes forgery, counterfeiting, handwriting analysis and other related subdisciplines.
Criminal Law.
Criminal Law serves to define offenses under a codified system of laws and punishments. Basically, it is where society defines what a crime is and how it is prosecuted.
Forensic Photography.
Basic techniques of photography as they apply to investigative work.
Crime Scene Processing.
This includes all aspects of forensic science and how they come together when searching a crime scene, collecting evidence, tagging evidence, and analyzing evidence in a lab.