A more thorough explanation:

A cookie is a small piece of data that a website sends to a user's web browser. The browser stores this data in a text file and sends it back to the server each time the browser accesses the server. The main purpose of a cookie is to help the server identify the browser.

For example, when you log into a website, the website may use a cookie to remember your login information. This way, you don't have to enter your username and password every time you visit the site.

However, cookies can also be used to track users and collect information about their browsing habits. In some cases, this can be a privacy concern.

In 2000, the U.S. government set strict rules on setting cookies after it was discovered that the White House Drug Policy Office used cookies to track users viewing its online anti-drug advertising. In 2002 and 2005, the CIA and NSA were found leaving persistent cookies on computers that had visited their websites. This raised concerns about privacy and led to lawsuits between corporations and web-monitoring companies.

Overall, cookies can be useful for improving the user experience on websites, but it's important to be aware of their potential privacy implications.