Shell may refer to: Architecture and design Shell (structure), a thin structure Concrete shell, a thin shell of concrete, usually with no interior columns or exterior buttresses Thin-shell structure Science Biology Seashell, a hard outer layer of a marine animal, found on beaches, when brought near to the ear one can hear the sound of the ocean. It can also be a small shelter for insects Eggshell Nutshell Exoskeleton, an external covering of some animals Mollusc shell Bivalve shell Gastropod shell Shell, of a brachiopod Turtle shell Physics and chemistry Electron shell or a principal energy level of electrons outside an atom's nucleus Nuclear shell model, a principal energy level of nucleons within an atom's nucleus On shell and off shell, quantum field theory concepts depending on whether classical equations of motion are obeyed Mathematics Spherical shell Organisations Shell plc, a British multinational oil and gas company Shell USA Shell Australia Shell Canada Shell Nigeria Shell corporation, a type of company that serves as a vehicle for business transactions Computing Shell (computing), a type of user interface Command-line interface, sometimes referred to as command shell List of command-line interpreters, programs occasionally referred to as shells Web shell, interface that enables a web server to be remotely accessed Read–eval–print loop, also known as a language shell Shell account, a user account on a remote server Secure Shell, cryptographic network protocol Shellsort or Shell sort, a sorting algorithm by Donald Shell Shell, an empty expert system Entertainment Shell (film) Shell (theater), a curved surface for reflecting sound The Shells, a musical group "Shells" (Angel), a TV episode Shell, a receptacle used in the Shell game Places Shell, Ecuador Shell, Wyoming, United States Shell Lake (disambiguation), several places Weaponry Shell (projectile), an explosive device fired from artillery Shotgun shell, a type of shotgun ammunition Persons with the surname Shell Art Shell (born 1946), American football player and coach Brandon Shell (born 1992), American football player Donald Shell (1924–2015), American computer scientist Donnie Shell (born 1952), American football player George W. Shell (1831–1899), U.S. Representative from South Carolina Karl Shell (born 1938), American economist Other uses Racing shell, a watercraft Shell (machinery), each half of a two-piece plain bearing Coverage shell, the number of defenders guarding the deep portion of the field in American football Conchiglie, a type of pasta See also Shell suit, a descendant of the tracksuit Shel (disambiguation) Shels (disambiguation) sv:Skal