Hi makenzi.exc,
The http-equiv attribute provides an HTTP header for the value of the content attribute.
This attribute can be used to simulate an HTTP response header.
Syntax
<meta http-equiv="content-security-policy|content-type|default-style|refresh">
content-security-policy - Specifies a content policy for the document.
<meta http-equiv="content-security-policy" content="default-src 'self'">
content-type - Specifies the character encoding for the document.
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
default-style - Specified the preferred style sheet to use.
<meta http-equiv="default-style" content="the document's preferred stylesheet">
refresh - Defines a time interval for the document to refresh itself.
<meta http-equiv="refresh" content="30">
Refresh document every 30 seconds.