what is Performance metrics for web application?

Performance metrics are measurements used to evaluate the efficiency and effectiveness of a system. TTFB, or Time To First Byte, is a performance metric that measures the time it takes for a browser to receive the first byte of data from a web server after making a request.

TTFB is important because it can affect the overall user experience of a website. A slow TTFB can cause delays in loading the website and make it feel unresponsive to the user.

Other performance metrics that are commonly used in web development include:

• Page Load Time: Measures the time it takes for a web page to fully load and become usable by the user.
• Render Time: Measures the time it takes for a web page to display its content on the user's screen.
• Time To Interactive: Measures the time it takes for a web page to become fully interactive, where users can click buttons, scroll, and perform other actions on the page.
• Number of Requests: Measures the total number of requests made by the browser to the server to load a web page.
• Page Size: Measures the total size of a web page, including all images, scripts, and other resources that are downloaded to the user's browser.