CSS embedded, inline, and external differences

In the process of learning CSS, often use embedded, inline and the three kinds of outreach, and then I will learn a little bit about myself:

1. Embedded

<! DOCTYPE html>"en">    <meta charset="  UTF-8">    <title></title>"  color:red; ">web front 
Similar to the code:
In this code, the H1 tag is inserted in the
Style= "color:red. This is called embedding, relatively simple and relatively easy to understand.
2. Inline
<! DOCTYPE html>"en">    <meta charset="  UTF-8">    <title></title>    <style>           h1{              color:red;               }
    <style>
Inline formats such as code, the properties to be declared are in 
3., outreach
<! DOCTYPE html>"en">    <meta charset="  UTF-8">    <title></title>
. h1{color:red}
The first figure of the code is written in HTML, and the second diagram of the code is written in the CSS, so that the source code and attribute values can be written separately, so much more concise, in the face of large paragraphs of writing to greatly reduce our writing difficulty has been error rate.
The above is a simple understanding of the contents of these three ways of learning.
CSS embedded, inline, and external differences