In Oxford Companion to Law, crime has been defined as "an act done in violation of those duties which an individual owes to the community and for the breach of which the law has provided that the offender shall satisfy the public".
In other words, any wrong done against the society is termed as a crime; and criminal is the one who has committed this act against the society, which has been made punishable under the law. The crime that we talk about is generally intentional. Thus when it comes to an individualistic outlook or the society as a whole, precautionary protection from these criminals is the only thing that strikes a layman. Their alarm in actual, is not the ill act committed by the culprit in the past, but the probability of occurring the same in the future. As a result, the criminals are often detested by the society.

Thus when we talk of crime and criminals, we basically have to understand the approach of an individual to perceive criminal conduct. Though we can adopt many strategies to categorize the criminals depending upon the diversity of perceptions that come through, but going in accordance with the general contemporary line of perceptional thoughts and taking economical, psychological and various other factors in to consideration, criminals can mainly be classified into the following five categories, namely:

-         Congenital Criminals: These are the ones who commit crimes due to hereditary reasons.

-         Maniacal Criminals: These are the ones who commit crimes due to psychological reasons.

-         Customary Criminals: These are the ones who commit crimes under the influence of physical and social environments.

-         Criminals by zeal: These individuals though are fit and healthy, but commit unlawful activity under the influence of extreme emotions like anger, jealousy and remorse.

-         Sporadic Criminals: These are the criminals which were not criminals by nature, but they some how committed unlawful activities under atrocious conditions.

So it is quite palpable that even if the crime is the same, the intention and the conditions under which the crime was committed may vary from person to person. Thus it was devised that indistinct periods should be set keeping in view the conditions under which the crime substantialized, the latent harm the culprit is capable of, and the chances of his adaptation and adjustment in the society. Accordingly wooly sentences with maximum period limits are now prevalent in many countries across the globe.

Though individualistic approach was good, but somewhere somehow, it has lost much of the integrity with the introduction of more sophisticated and accurate theories. Though there were other reasons as well which led to its elimination, the most important being the fact that individualistic approach in some way fails to understand that crime is a socio-cultural phenomenon and is not associated with the physical or psychological equipment of an individual. It cannot, on the other hand, be denied that the law-makers gave all ears on the overall traits of the culprits rather than other unimportant factors, which was a step forth in the right direction towards understanding criminology and judging criminal acts in a better manner.