You Can Develop All Html Tags in Html Editor Else Html and Head And body Tag Because its included Default in page You can use Design Tool to desgin page or Use Code editor and write Html tags .As You See Anything You Design Using Tools like table or Else you See it Code in Code Editor Also If You Write html tag in Code Editor and press save you will see the result in Designer TextBox.You can Copy Design from any website and paste it in designer Page easly also you can Code any Code in code Editor
Don't publish any page unless you check the whole code also you can preview the page before published by press preview item in file menu.
After Develop Code Save the page but uncheck published code then press preview button in upper left of page to check if page work prefect or not so you edit it untile come fine then you can checked it again .
