< img src="picture.jpg" > The "picture.jpg" file is located in the same folder as the current page
< img src="images/picture.jpg" > The "picture.jpg" file is located in the images folder in the current folder
< img src="/images/picture.jpg" > The "picture.jpg" file is located in the images folder at the root of the current web
< img src="../picture.jpg" > The "picture.jpg" file is located in the folder one level up from the current folder