HTML documents contain elements and text.
Elements are represented using tags.
Different devices may display HTML differently.
Every document must have a single root element.
Special characters must be written using escape sequences beginning with &.
Elements can be customized by adding key-value pairs called attributes.
An element’s attributes must be unique, and are unordered.
Attribute values should not have any internal structure.
Put metadata in meta elements in a page’s head element.
Use ul for unordered lists and ol for ordered lists.
Add comments to pages using <!-- and -->.
Use table for tables, with tr for rows and td for values.
Use img for images.
Use a to create hyperlinks.
Give elements a unique id attribute to link to it.