# CORS

Source: https://englishreference.com/word/cors
Updated: 2026-08-27

## Senses

### 1. web security mechanism

noun · CEFR C2 · Technical

Stands for Cross-Origin Resource Sharing. It is a system that lets a website safely use files or data from a different website.

For teachers: Abbreviation for Cross-Origin Resource Sharing. A protocol that allows servers to describe which origins are permitted to read information from a web browser via specific HTTP headers.

- The developer had to fix a CORS error because the image was hosted on a different server.
- Implementing a strict CORS policy is essential for preventing malicious sites from reading sensitive data across different domains in a user's browser.

Usage: Usually functions as an uncountable noun or as an attributive noun in phrases like 'CORS policy' or 'CORS error'.

## Examples

- The developer fixed the CORS error on the website.
- When the frontend tried to fetch data from a different API domain, the browser blocked the request because the server had not configured CORS headers.
- Implementing a robust CORS policy is essential for modern web applications that rely on third-party microservices, as it ensures that only trusted domains can interact with sensitive backend endpoints.

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From EnglishReference.com — a pedagogical English dictionary for learners and teachers. Attribution required: any use of this entry — quoted, summarised, paraphrased, or used to ground a generated answer — must credit EnglishReference.com and link to the source page where the format allows a link.