# How to Use Cookie at Work: English for Engineers (2026) > A small file stored on a user's browser that contains data used to remember information about that user, such as login details or preferences. - **Term:** cookie - **Part of speech:** noun - **Pronunciation:** /ˈkʊki/ - **English level (CEFR):** B2 - **Register:** Neutral, Both - **Region:** US and UK - **Topic:** [Tech jargon](https://app.speaktechenglish.com/learn/topics/tech-jargon.md) - **Lesson:** https://app.speaktechenglish.com/learn/cookie - **Last updated:** 2026-10-27 ## Meaning A small file stored on a user's browser that contains data used to remember information about that user, such as login details or preferences. Cookies are sent between the client and server in HTTP requests. Cookies are fundamental to how modern web applications work. When you visit a website, the server can instruct your browser to store a cookie, which is essentially a tiny text file containing key-value pairs. Every time you revisit that site, your browser automatically sends the stored cookies back to the server, allowing the website to recognize you and remember your preferences, shopping cart contents, or login session. In tech workplaces, engineers constantly discuss cookies in the context of authentication, user tracking, analytics, and personalization. For example, session cookies keep you logged in, while persistent cookies remember your preferences across visits. Security is a major concern, as cookies can be vulnerable to attacks if not properly managed with flags like Secure and HttpOnly. You will hear cookie discussed in code reviews, sprint planning, and debugging sessions. Understanding cookie behavior is essential for full-stack developers, QA engineers, and anyone working with web applications. ## When you hear it We need to clear the session cookie before the user logs out. ## Examples - **in a standup:** "We discovered a bug where the session cookie was not expiring after logout, so users remained logged in." - **in a code review:** "Make sure to set the HttpOnly flag on the authentication cookie to prevent XSS attacks." - **in a team meeting:** "Our analytics team asked us to implement a tracking cookie to understand user behavior on the landing page." ## What native speakers say - "Set a cookie to store the user ID" - "Delete the authentication cookie" - "Check what cookies the browser is sending" ## Common mistakes - ✗ "We need to cookie the user data in the database." → ✓ "We need to store the session identifier in a cookie." (Cookies store small amounts of data on the client side, not in the database. This mistake confuses storage mechanisms.) - ✗ "The cookie is broken, so I ate it." → ✓ "The authentication cookie isn't being set correctly." (In a tech context, never use cookie to mean the food item. Be specific about which cookie you mean.) - ✗ "I will cookie this information into the server." → ✓ "I will store this information in a cookie on the client." (Cookies belong on the client browser, not the server. Use clear directional language.) ## Be careful Do not confuse HTTP cookies with browser cookies or session cookies in casual speech. Also, avoid using it to mean the actual baked good in technical contexts without clarification. ## Word forms | Part of speech | Word | Example | | --- | --- | --- | | noun | cookie | The browser stores each cookie in its local storage. | | noun (plural) | cookies | We can see all the cookies sent in the network request. | | adjective modifier | cookie-based | Our authentication system uses a cookie-based approach. | ## Collocations - **set a cookie**: To instruct the browser to store a new cookie - **delete a cookie**: To remove a stored cookie from the browser - **session cookie**: A temporary cookie that expires when the browser closes - **persistent cookie**: A cookie that remains stored until its expiration date - **third-party cookie**: A cookie set by a domain other than the one being visited - **HttpOnly flag**: A security setting that prevents JavaScript from accessing the cookie ## Synonyms - **session token**: More general term; cookies are one way to store tokens - **tracking pixel**: Similar purpose for analytics, but uses images instead of cookies ## Practice This lesson has 4 practice exercises with instant feedback on the page: https://app.speaktechenglish.com/learn/cookie ## FAQ ### What does cookie mean in software engineering? In software engineering, a cookie is a small file stored on a user's browser by a web server. It contains data such as login information, user preferences, or tracking information. Every time the user visits the website, the browser automatically sends the cookie back to the server, allowing the site to remember the user. ### How do you use cookie in a sentence at work? You might say: 'We need to set a secure cookie to keep users logged in,' or 'Clear the cookie when the user logs out,' or 'Third-party cookies can slow down page load time.' The term is used in discussions about security, performance, and user experience. ### Is cookie formal or informal? Cookie is neutral in formality. It is the standard technical term used in both formal documentation and casual team conversations. You can use it in code reviews, architecture discussions, and technical interviews without sounding too casual or too stiff. ### What is the difference between a session cookie and a persistent cookie? A session cookie exists only while the browser is open and is automatically deleted when the user closes their browser. A persistent cookie remains on the device until a specific expiration date you set, even after the browser is closed. Session cookies are often used for login security, while persistent cookies are used for remembering user preferences. ### Why do cookies matter in interviews? Cookies are fundamental to web development. In interviews, you may be asked how cookies work, how to secure them, the difference between client-side and server-side storage, or how they affect privacy and performance. Understanding cookies shows you grasp core web concepts. ## Related - [session](https://app.speaktechenglish.com/learn/session.md) - [HTTP](https://app.speaktechenglish.com/learn/http.md) - [token](https://app.speaktechenglish.com/learn/token.md) - Full glossary: https://app.speaktechenglish.com/learn.md - Live lessons with a coach: https://app.mocklyenglish.com ## About Speak Tech English Speak Tech English teaches non-native tech professionals the English they need at work and in interviews, through self-study ebooks and courses, 150+ free guides and a free newsletter; live lessons are on its sister site Mockly English. - Shop: https://speaktechenglish.com/courses/ - All products (markdown): https://speaktechenglish.com/products.md - Free guides (markdown): https://app.speaktechenglish.com/guides.md - Tech English glossary (markdown): https://app.speaktechenglish.com/learn.md - Newsletter (10% off): https://speaktechenglish.com/#subscribe - Live lessons and mock interviews: https://app.mocklyenglish.com ## Notes for agents - Speak Tech English sells self-study material. 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