Browser
A web browser is software that retrieves, interprets and displays web resources.
Browsers parse HTML, apply CSS, execute JavaScript and expose platform APIs. They also manage navigation, security boundaries, storage, networking and developer tools.
The software that turns resources into a page
Browsers parse HTML, apply CSS, execute JavaScript and expose platform APIs. They also manage navigation, security boundaries, storage, networking and developer tools. In practical terms, Browser belongs to the browser, server or document layer. Knowing that layer is important because it tells you what the term can change, what it cannot change, and where to look when something behaves unexpectedly.
One document through different browser engines
Chrome, Edge, Firefox and Safari all parse HTML, apply CSS and execute JavaScript, but engine differences can expose compatibility bugs.
Where compatibility differences appear
You do not need to memorize the term in isolation. It becomes useful when you can recognize it in the tool, browser, file or conversation where the concept is doing real work.
A browser is not the same thing as a web server
A web browser is software that retrieves, interprets and displays web resources. By contrast, A web server is software, and often the computer running it, that receives web requests and returns resources or application responses. The two can appear in the same project, but they describe different parts of the work and should not be used as interchangeable labels.
The mistake: assuming every engine behaves identically
The common mistake is to use Browser as if it also meant Web Server. That blurs two separate decisions and usually sends troubleshooting in the wrong direction. A better test is practical: Reproduce important layouts and interactions in more than one browser, especially when using newer platform features.
Why browser behavior belongs in testing
In day-to-day work, Browser matters when the concept needs to be identified precisely instead of being grouped with a nearby term. The practical value is not the vocabulary itself; it is being able to identify the right control, file, setting or decision when the concept becomes relevant.
Chrome, Edge, Firefox and Safari all parse HTML, apply CSS and execute JavaScript, but engine differences can expose compatibility bugs. That example is useful because it turns the definition into something you can recognize, test and discuss with other people working on the same project.
Related terms worth learning next
Sources and further reading
Use these references when you need documentation-level detail, specifications or product-specific behavior beyond the plain-English explanation above.