Predation refers to the consumption of one organism known as prey by another known as predator in which the prey is alive when the predator attacks him for the first time. Predation is beneficial to the predator and harmful to the prey. This is a large group that covers a wide variety of interactions and many types of predators. For the purposes of this essay, we will focus on classifying predators based on their individual taxonomic and functional responses. When predator and prey meet, they interact with each other. Natural predators appear to regulate prey numbers. This brings us to a key question that this essay attempts to answer: if the number of prey increases, can the predator quickly adjust its prey capture rate to take advantage of the situation? Predators called cautious predators select the highest quality prey and will switch prey when other foods become more profitable. Cautious predators show a preference for the prey they consume, in order to maximize the net energy gain per unit time. An important factor in predation-prey interactions is the speed with which individual predators can capture individual prey. The response of predator consumption rate to increasing prey density is called the functional response. Probably the simplest method for classifying predators is the taxonomic classification system. Carnivores are predators that consume animals. True predators kill their prey immediately after attacking them. During their life, they kill many preys. This involves consumption of carnivores, for example lions, snakes, seagulls and carnivorous plants. Even plankton feeding on large mammals, seed feeding rodents and ants are included in this classification. Grazers attack a huge density of prey. Examples include slugs feeding on grass. Handling time is the time required to catch, kill, process, eat and digest the prey. Handling time varies for different types of prey. As prey density increases, finding prey becomes easy, but handling prey still takes the same amount of time. The consumption rate reaches a maximum determined by the maximum number of handling times that can be integrated into the total time. A type three functional response occurs in predators that increase their search activity with increasing prey density. Initially, there is a slow increase in predation rate at low prey density, then mortality increases with increasing prey density, and then declines. Examples include a fly feeding on sugar. The graph shows changes in the number of prey attacked per unit time by a single predator as initial prey density varies..