Updated Sept 22, 2020 · 4 min read

What are cookies?

A cookie is a small amount of information generated when you visit a website and saved by your web browser. Cookies provide a way for websites to remember you, your preferences, and your activity. You might also see cookies referred to as web cookies, internet cookies, browser cookies, or HTTP cookies.

When are cookies used?

Cookies are used by websites to track your activity and behavior. This isn’t always a bad thing. Cookies have many benefits that help users by tailoring a website experience to the user, providing a better user experience.

Online retailers use cookies to keep track of the items in your shopping cart as you explore their website. Without using cookies, the website would lose track of your shopping cart items when you go to another website. They might also use cookies to suggest or feature products that match your shopping history.

Financial institutions use cookies to remember your login information when you select a Remember me checkbox. Each time you return to the website for your bank, the site fills in your username and sometimes even your password using a login cookie. Other websites remember other types of form fields, like your phone number or address.

Types of cookies

Different types of cookies are used to keep track of different kinds of activity. The following are some of the most common types of cookies.

Session cookies

Session cookies (or in-memory cookies) are used when you’re currently using a website. Once you close your web browser, any session cookies are deleted. Because these cookies don’t have an assigned expiration date, your web browser knows it's a session cookie.

Persistent cookies

Persistent cookies are used for long-term records of multiple visits to a website. These cookies expire at a specific date or after a certain amount of time. From the time your web browser saves the cookie to the time it expires, information is transmitted to the server the each time you visit the website it belongs to.

Third-party cookies

Third-party cookies are cookies that don’t belong to the domain that’s shown in your address bar. Third-party cookies appear when you visit a website that features an external advertisement. These cookies are often used by advertisers to provide you with more relevant advertisements.

Zombie cookies

Zombie cookies are cookies that are automatically recreated after they’re deleted. They work by storing the information from the cookie in multiple locations. These types of cookies can be difficult to manage.

Incognito mode

Modern web browsers include privacy settings that enable you to block third-party cookies. When you use Google Chrome as your web browser, you can browse in incognito mode so your web browser doesn’t record your browsing history. Cookies created while you’re in incognito mode are deleted every time you close a window that’s in incognito mode.

Related Terms


Web browsers (or “browsers”) are software applications used for accessing and viewing information on the internet.


A server is a computer that provides a service (such as providing data) to other computers and its users, known as the clients.

User Interface

A user interface (UI) is the point at which humans interact with and control software applications or hardware devices.