webmaster 
What is a cookie and What do they do?
According to Wikipedia, HTTP cookies are small blocks of data created by a web server while a user is browsing a website and placed on the user’s computer or other devices by the user’s web browser. Cookies are placed on the device used to access a website, and more than one cookie may be placed on a user’s device during a session.
There are actually several variants of website cookies that accomplish different things. As examples we can give:
- Session cookies: allow users to be recognized within a website so any page changes or item or data selection done is remembered from page to page.
- Secure cookies: A cookie with the secure attribute prevents cookies from being observed by unauthorized parties.
- Third-Party Cookies: primarily collect marketing-relevant information such as age, origin, gender, and user behavior data, and through this collection are powerful online marketing tools, especially for personalized advertising.
Pros and Cons of Cookies
Pros
- Online Shopping Experience: Users are able to add products to their carts, close the page and return to it later with them still present.
- Form Submissions: Cookies can remember submitted information such as names and other fields on a form.
- Personalization: Cookies can also help store language preferences and currency preferences as well.
- Suggested Content: You can see this occur on shopping sites with a “Related Searches” feature. It relies on cookies to collect data, cross-reference it with other users who have a similar profile, then makes its recommendations.
- Security Authentication: When entering a session, this allows web servers to know whether a user is logged in. If you don’t allow cookies, websites will never remember that you’re logged in.
Cons
- Privacy: Most browsers are set to accept cookies by default. As a result, cookies are stored “invisibly” on your local machine every time you browse the internet. As a result, your browsing history and IP address become public knowledge.
- Local Storage: These “little” website cookies are actual files stored on your hard drive. The more you visit, the more that is stored. As it builds over time, it can take up quite a bit of storage space on your computer/mobile device.
- Unauthorized Data Collection: Websites may sell the information collected from cookies to third parties or use it to hack into social networks or other online accounts.
Are website cookies bad?
It depends. Though it improves the browsing experience, It also shows some privacy concerns. You literally share your information (Age, Origin, Interests, etc) with different parties. Those information might be sold to marketing companies or used by hackers to steal your identity on the Internet. So before accepting third-parties cookies on website, please be aware of those facts.
