Final answer:
The '&' character after a command in Unix-like systems places the command in the background, allowing users to continue working while the command runs.
Step-by-step explanation:
In the context of operating systems, especially Unix-like systems such as Linux or OSX, the '&' character at the end of a command is used to run the command as a background process. This means the terminal or command line interface (CLI) does not wait for the command to finish before allowing the user to enter another command. Rather, the system runs the command in the background, providing the user with the prompt immediately to run more commands concurrently.
For example, if you were to run 'program &', the 'program' would start executing, but the command line would return immediately, allowing you to continue working on other tasks without having to wait for 'program' to finish.