When the backend is on https, what is the meaning of the "self-signed certificate error" in Nuxt3 Js?

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When the backend is on https and there is a "self-signed certificate error" in Nuxt3 Js, it means that the SSL certificate used by the backend server is not trusted by the browser. This is because the SSL certificate is not signed by a trusted certificate authority (CA). Self-signed certificates are often used for development purposes, but they can cause security warnings in production environments. Browsers will display an error message to the user to inform them that the SSL certificate is not trusted, and may prevent them from accessing the website. However, this error can be ignored in a development environment by adding an exception to the browser.