Cookies have been around about as long as the World Wide Web. They are small pieces of data, text files stored on your computer or other device when you load a website in a browser.

Back in the 1990s, lots of sources would tell you to delete the cookies on your computer. People treated them like a kind of spyware. They can be useful. They remember your email and information for forms. They remember passwords that you want remembered. They remember preferences and allow users to register and remain logged in.

As with the sweet and crunchy kind, there are different kinds. A cookie can be just for one visit to a site – a “session cookie” or for multiple visits – a “persistent cookie.”  First party cookies are set by the site that you are visiting, but there are also “third-party cookies” set by other websites who serve up content on that site.

The European Union is concerned about cookies. They have an  ePrivacy Directive (often referred to as the ‘cookie law’) which places requirements on website owners and operators to provide information about, and gain consent for their use of cookies. I have visitors from outside the United States, so I have added the option to this site to opt out of cookies from the site.

This site is hosted on WordPress.com and it makes use of cookies for a variety of different purposes. They offer users a widget to inform and allow consent for cookies. You probably saw that the first time you visited the site, but it might be useful to know more about those cookies are used.

One technical one is akm_mobile which stores whether a user has chosen to view the mobile version of the site.

If you are a registered WordPress.com user, then a twostep_auth cookie is set when you are logged in using two factor authentication. Another cookie – wp-settings-{user_id} is useful to me as a user because it allows my user wp (WordPress) admin configuration for the site.

Some cookies are pretty innocent, such as cookietest which checks if cookies are enabled, and  botdlang which tracks the language a user has selected.

Performance cookies collect information on how you interact with websites and WordPress says this analytical data is only used to improve how a website functions. An example is the ab cookie used for AB testing of new features.

Restricting or disabling cookies can limit the functionality of sites, or prevent them from working correctly at all. Still, people might not like the use of ones like advertising cookies that are used to display relevant advertising to visitors. They track details about visitors such as the number of unique visitors, number of times particular ads have been displayed, the number of clicks the ads have received, and are also used to measure the effectiveness of ad campaigns by building up user profiles.

Sites often use third-party applications and services such as social media platforms. When you use a Facebook or Twitter sharing button or embedded video from YouTube and Vimeo, cookies may be set by these third parties, and used by them to track your online activity. (I don’t have any direct control over the information that is collected by these cookies and either does WordPress.

You can choose to restrict the use of cookies, or completely prevent them from being set. Most browsers provide ways to control cookie behavior, such as the length of time they are stored.

To learn more about how to manage cookies, see aboutcookies.org. For more about advertising cookies and how to manage them, see youronlinechoices.eu (EU based), or aboutads.info (U.S.-based).