Step 1: Cookie Definition.
A cookie is a small text file saved by the web browser on the user's computer when requested by a website. It aids the website in recalling user preferences, login states, and other minor data.
Step 2: Option Analysis.
- Option 1: Incorrect → Cookies reside on the client's computer, not the server's.
- Option 2: Correct → Only the originating website can access or alter a cookie, which is stored client-side.
- Option 3: Incorrect → Users do not create cookies; websites generate them.
- Option 4: Incorrect → Cookies are not security mechanisms, although they can store authentication tokens.
Step 3: Clarification.
Cookies enhance user experience by maintaining session status, shopping cart contents, and preferences. Their inherent security is limited, and improper use can compromise privacy.
Final Answer: \[\boxed{\text{Cookies are stored on the client machine and only editable by the site that created them.}}\]