The confusion of Cross-domain problems in Hybrid app

the environment of the front-end web page is a browser, and there are cross-domain problems. Hybrid app is in the webview component of app. My understanding is that webview is a small browser and should also have cross-domain problems.
webview uses the file protocol to load local static resource pages. Will there be a cross-domain problem if I initiate a http request in my static js file, such as a https://a.com?search=1 dagger post or get request?

recently, in the development of mixed applications with ionic, there will be cross-domain problems in browser development. In the development, we have directly disabled the browser policy. However, after being packaged into app, you can make normal ajax requests while the phone is running, without cross-domain problems.
Please explain in detail. I am very upset about this when I first started at the front end.

Feb.09,2022
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