Difference between res.setHeader and res.header in node.js

Question

What is the difference between res.setHeader and res.header. Which one should be used for enabling CORS? In some pages res.header is used and some pages res.setHeader is use

Answer 1

Perhaps an example can clarify more:

// single field is set 
res.setHeader('content-type', 'application/json');

// multiple files can be set
res.set({
     'content-type': 'application/json',
     'content-length': '100',
     'warning': "with content type charset encoding will be added by default"
  });