Shell

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

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

Shell plc, a British multinational oil and gas company
Shell corporation, a type of company that serves as a vehicle for business transactions

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

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