type and which Commands in Linux

Linux provides powerful tools for managing and inspecting commands within the terminal. Among them, the type and which commands allow users to understand how a command is interpreted by the shell and locate executable programs within the system.
This article explores how these commands work, their differences, and when to use each.
The type Command—Identifying Command Types The type command is a shell builtin that helps determine how the shell interprets a given command. It is useful for identifying whether a command is a builtin, an alias, or an executable file.
Basic Usage Where command is the name of the command to inspect.
Examples

Command	Result
type type	Displays "type is a shell builtin"
type ls	Shows that ls is an alias, e.g., ls --color=tty
type cp	Indicates cp is an executable located at /bin/cp

Key Insights from type Builtins: Commands that are built directly into the shell, such as type. Aliases: Commands that are shortcuts for other commands with specific options, such as ls --color=tty. Executables: Commands stored in system directories, like /bin/cp.
The which Command—Locating Executable Programs The which command helps determine the exact location of an executable program. This is useful when multiple versions of a command exist on a system, particularly in server environments.
Basic Usage Where command is the name of the executable to locate.
Examples

Command	Result
which ls	Returns /bin/ls, confirming its location
which cd	Shows an error because cd is a shell builtin, not an executable

Key Insights from which Works only for executable programs (not builtins or aliases). Helpful in identifying which version of a command is being executed. Useful in environments with multiple installations of the same command.
Comparison of type vs which

Feature	type	which
Determines if a command is a builtin, alias, or executable	✔️	❌
Finds the exact location of an executable	❌	✔️
Works for builtins, aliases, and executables	✔️	❌ (executables only)
Commonly used for troubleshooting command behavior	✔️	✔️

Conclusion The type and which commands provide valuable insights into how commands function in Linux. Use type to determine if a command is a builtin, alias, or executable. Use which to locate the exact path of an executable.