A session ID or session identifier is a piece of code that identifies a user and their actions on a website. If you use Google Analytics, you will notice the reports are organized under users, sessions and interactions. Sessions allow analysts (people who interpret the Google Analytics reporting) to gain valuable insights into how your site is being navigated as well as provide information on where your site may not be functioning correctly.
I want to quickly explain the difference between cookies and sessions and how they work together. Sessions are a collection of recorded interactions a specific user has on a website for a designated period of time. A session not only shows what pages are visited, but can record transactions, downloads, form submissions and click paths. A session will expire after 30 minutes if their is an inactive user. As long as a user is always interacting, the session will continue.
Cookies store information within a browser and are created when a user’s browser loads a particular website. This is what allows your browser to perform specific functions including remembering login information and storing information within websites you have visited. This would include your name, address, phone, email and credit card purchases. Cookies are transmitted back and forth between browser and website and are stored in your browser folder and accessed by your browser when you visit the same website that created the cookie. They are used by developers to help users navigate websites efficiently, enabling fields to pre-populate with information you provided on your last visit.
Cookies are also instrumental in storing the information needed for a website, an ad or widget to render correctly within your browser or device. There are several browsers (ie: Internet Explorer, Firefox, Chrome) and all browsers render websites differently. The cookies store your browser and device information, allowing the website to know what version of their site to display. The same goes for ads, widgets and other elements that display on your website.
Sessions and cookies work together to help in the conversion (purchasing) process. Webpages have no memory, so unless cookies are enabled, a website cannot store the information needed to recognize a current or returning user. Session cookies are especially important with a shopping cart feature on an e-commerce site. Websites use session cookies to keep track of movement from page to page and remember the items you selected in your shopping cart. Without session cookies, a website is not able to recognize you as a current user and therefore cannot remember what is in the shopping cart after you leave the shopping cart page. The cookies store your shopping cart items and purchase history, making the conversion process smooth and seamless.
Benj Arriola, Vice President of SEO gives a quick summary of Session ID’s and explains some problems that arise and how to avoid those issues.