What are the characteristics of cookies?

The following are a list of characteristics of cookies:
1.Cookies are only sent back to the server that created them and not to any other server.For example,if a cookie was created by the Web server of www.macromedia.com and sent to the client or the browser,the cookie can be sent back to the same server only.
2.Cookies are only used by the server to find out the computer name,IP address or any other details of the client computer.