Difference Between Session and Cookies: Nuances to be Sure About

The main difference between sessions and cookies lies in where they are stored. Sessions are primarily used to manage user interactions and states during a single website visit. Cookies are smaller pieces of data stored on the browser of the user.

Sessions and cookies are useful tools for storing user data. They have different strengths and weaknesses. Each is an important tool for business sites to remember user information. But the way they work differs. 

It is important to know the difference between session and cookies for those getting into web development. But general internet users and marketers who value privacy will benefit from knowing the difference, too. 

In the following few minutes, we will highlight the differences between these two.

Session vs. Cookies: Quick Comparison

Aspect	Cookies	Sessions
Storage Location	Stored on the client-side (browser).	Stored on the server-side.
Lifespan	Can have varying lifespans, from seconds to years.	Active only during the user’s visit (session).
Purpose	Store small amounts of data (e.g., preferences, tracking information).	Manage user interactions and state during a single visit.
Data Size	Limited storage capacity (usually a few kilobytes).	Can store larger amounts of data.
Initiator	Initiated by both the server and the client.	Primarily initiated by the server.
Security	Can be less secure due to exposure to client-side manipulation.	Generally more secure as data is stored on the server.
User Interaction	Data is sent to the server with every HTTP request.	Interaction data is managed on the server, reducing data transmission.
Examples	Remembering login credentials, tracking user behaviour.	Managing shopping cart contents, user authentication.
Storage Control	Users can manage cookies through browser settings.	Managed by developers through server-side code.
Expiry Control	Cookies can have explicit expiration dates.	Sessions expire after a period of inactivity or when the user closes the browser.
Cross-Tab Sharing	Cookies are shared across tabs/windows of the same browser.	Sessions are generally isolated to the tab/window they are created in.

What are Cookies?

Cookies are small pieces of data that websites store on your computer or device when you visit them. Then, these pieces of data are sent by the website’s server and are stored in your web browser. 

How Cookies Work

The process of exchanging cookies happens between the user’s browser and websites. These are bite-sized, with a maximum file size of 4KB. They are text files that bear fragments of information. 

The websites the user visits stash cookies on their device. These cookies can store various information, from the chosen language to items in a virtual cart.

So, the next time they return to an online store, cookies remember what they liked and didn’t. 

Ever noticed how ads are tailored to one’s interests? That’s cookies at work.

Purpose of Cookies

• With cookies, websites remember the user’s actions as they navigate through different pages on the site.
• To tailor the user’s experience, a website uses cookies. They can remember their preferences, such as preferred layout or font size choices.
• Advertisers and website owners use cookies to track online behaviour. So, marketers use this information to deliver targeted ads or analyse how users interact with a website.

What are Sessions?

A session is a temporary and interactive connection between a user and a server. Sessions track and manage the interactions a user has with a website. It can be during a single visit or usage period with a certain threshold.

So, here is one of the major differences between session and cookies. 

Cookies reside on your device. Sessions find their home on the website’s server. 

This secure vault ensures that your data is fully secure from unauthorised access.

How Sessions Work

When a user visits a website, the server generates a unique identifier for that session. This identifier is a “session ID.” 

This session ID allows the server to associate the user’s interactions and data with their specific session on the server.

As the user navigates through the website, their actions and data are associated with their session ID. So, that allows the server to keep track of the user’s progress and store their temporary data.

It is important to remember that sessions have a limited lifespan. The session can expire if a user remains inactive for a specified period. Alternatively, sessions can expire when the user closes their browser. 

Purpose of Sessions

• Keeps tabs on user actions and data during a single visit.
• Stores temporary info (like cart contents) as users move around.
• Securely manages user-specific data on the server.