WEBVTT

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Now that you've seen a few sample
HTTP requests using telnet,

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I'd like to show you the overall
format of an HTTP request

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as stated in the specifications which
I've linked to in the teacher's notes.

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Here's how an HTTP request needs to look.

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HTTP request begin with request line.

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This starts with what's called
the request method, get or post.

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Know that there are other request
methods available on HTTP.

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They're outside the scope
of this course but

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I've linked to them in
case you're curious.

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In general the get request
method is used when you want to

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view a resource on the server
without making any changes.

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And post request are used for
actually making a change or

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update to the listed resource.

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We'll look at post request
later in the course.

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Speaking of the resource,
that's what's listed next, the URI, or

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again, Uniform Resource Identifier.

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If you want to view the root, or

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what's typically the home page,
you'll use a single slash here.

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Finally, HTTP is listed as the protocol
in use followed by a slash and

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ending with the version of HTTP,
currently 1.1.

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As a side note and heads up,
HTTP/2 is on the way.

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Don't worry though,

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HTTP/2 won't change any of the stuff
we're discussing in this course.

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And you'll be able to continue using
HTTP/1.1 likely for many years to come.

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For more info on HTTP/2,
check the teacher's notes.

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The next line begins with what's called
the header section of the request.

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This communicates information related
to the request being made, and

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can include all sorts of info.

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In this example, you see it includes
the host which we've discussed.

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The user agent which identifies
the exact device making the request

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I've listed telnet here and

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accept language which tells the server
which language we prefer for the response.

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There are lots of other
headers available and

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we'll see a bunch more throughout
the best of the course.

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Following the headers is a blank line.

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Then concluding the request,
is the request body, or

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what's frequently called the payload.

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If the headers refer to the information
related to the request,

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the payload refers to the data being
transferred in the request, if any.

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As we'll see, data needs to be transferred
when the purpose of the request

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is to change a resource on the server.

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For example,
consider the scenario of using a form to

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edit the first name of a contact
saved in your address book online.

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When you submit those changes,

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a post request is sent containing
the new first name in the payload.

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In general,
the exact changes to be made on the server

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will be contained in the payload
of the post request.

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You won't see a payload
in the get request.

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And there you have it,
the format for any HTTP request.

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With that said,

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let's turn to the other side of this
web conversation, the response.