The term 'essential part' can be defined as the most important or necessary element of something. This term can be represented by a variety of words, such as 'CORE, ' 'HEART, ' 'PITH, ' 'INTEGRAL, ' 'KERNEL, ' 'SOUL, ' 'GIST, ' 'MARROW, ' 'ESSENCE, ' 'MEAT, ' 'MAINSTAY, ' and 'MEAT and potatoes.' Each of these words has its own unique connotation, but all of them refer to the same concept: the essential part of something. For example, the CORE of an apple is the essential part, as it contains the seeds that will eventually grow into a new tree. The HEART of a person is also an essential part, as it is the organ responsible for pumping blood throughout the body. The PITH of a plant is the essential part, as it is the innermost layer of the stem and contains the majority of the plant's nutrients. The INTEGRAL part of a machine is the essential part, as it is the component that holds all the other parts together. The KERNEL of a nut is the essential part, as it contains the edible part of the nut. The SOUL of a person is the essential part, as it is the intangible part of a person that makes them unique. The GIST of a story is the essential part, as it is the main idea or theme of the story. The MARROW of a bone is the essential part, as it is the innermost layer of the bone and contains the bone's cells. The ESSENCE of a perfume is the essential part, as it is the main ingredient that gives the perfume its scent. The MEAT of a sandwich is the essential part, as it is the main filling of the sandwich. The MAINSTAY of a community is the essential part, as it is the people or organizations that provide stability and support to the community. Finally, the MEAT and potatoes of a meal is the essential part, as it is the main course of the meal.