Dot (Unix)
Encyclopedia
. called the dot command is used to execute its first argument, a file. It's possible to specify arguments in a second argument. The first argument file does not have to be executable, but must be accessible via a directory defined in the PATH
environment variable. The dot command is often used to define environment variables that are accessible within the current process. In contrast to file executed directly as an executable, there won't be a new process opened and the environment definitions defined within apply to the current process or the current shell.
The dot command should not be confused with the dot file.
Path (variable)
PATH is an environment variable on Unix-like operating systems, DOS, OS/2, and Microsoft Windows, specifying a set of directories where executable programs are located...
environment variable. The dot command is often used to define environment variables that are accessible within the current process. In contrast to file executed directly as an executable, there won't be a new process opened and the environment definitions defined within apply to the current process or the current shell.
The dot command should not be confused with the dot file.