- HTML elements are added to the content of a page to describe its structure. An element consists of the opening and closing tags, plus its content.
- Tags usually come in pairs with an opening tag and a closing tag. There are a few empty elements with no content, (e.g., <img>). They have one self-closing tag.
- Opening tags can carry attributes, which tell us more about that element. Attributes have a name and a value. The value is usually given in quotes.
- CSS uses rules to indicate how the contents of one or more elements should be displayed in the browser. Each rule has a selector and a declaration block.
- The CSS selector indicates which element(s) the rule applies to. The declaration block contains rules that indicate how those elements should appear.
- Each declaration in the declaration block has a property (the aspect you want to control), and a value, which is the setting for that property
If you want to recap and practice your HTML skills: W3schools HTML
If you want to recap and practice your CSS skills: W3schools CSS