JSONP: Only get request is supported. Requests are sent through tags that support requests, such as Script, IMG, link, iframe, etc. After receiving the request, the server will convert the parameters sent by callback together with the required data into JSON data and send it back to the client. After receiving the request, the client will execute it directly.

Cors: Support get, POST, head request, using AXIos or jQuery to send the request, but note that origin on the back end should set the wildcard or request address (* or can only set a request address), request header should be set

Proxy: set the domain name that allows cross-domain requests and requests. Its principle is to simulate a server to request the server and return data to us