The cookies in Internet is not the same as the cookies we eat. It is a kind of files which record your login information and other browsing activity. For example, if you sign in Facebook and click the page, at the second time you open Facebook you don't need to sign in again, for that your cookies sign in the website instead of you. This function is quite convenient and save much time for you but has some risks on security as someone else may visit your Facebook without signing in. The cookies will be expired automatically after some time, and you can also delete them manually. Here are the steps on how to delete cookies in Chrome.
Steps - How to Delete Cookies in Chrome
Then a window will be opened. You need to choose the items that you want to clear. Tick off the checkbox before the items you want to delete such as "Cookies and other site and plug-in data". Then you need to choose the time from which the data will be obliterated. Finally, click on the button "Clear browsing data" to operate the deletion.