How do I cut or copy and paste a photo from a website to my desktop?

Question

I cannot cut or copy a photo from any website and paste it to my desktop. How do I do this?

Answer 1

http://support.apple.com/kb/HT2477
Pointing, clicking, and getting around
When you move your mouse or finger on a trackpad, you control a pointer (also known as a cursor) that moves across your screen. The pointer allows you to select and interact with the various items on your screen, including selecting files, clicking buttons, dragging sliders, and so on. Sometimes the pointer may look like a hand, a crosshair, an I-beam, or another icon, depending on what you're doing and the application you're using.
For example, if you're using Safari to view this webpage and move the pointer across it, notice that it turns into an I-beam when you move it over text or a text field. When you see this, you can usually interact with the text or field below it. When you move the pointer over a button or link, the pointer turns into a hand, letting you know that you can click on the item.
Depending on what you're doing and what application you're using, your pointer (far left) may change appearances
Clicking your mouse button or trackpad button once allows you to select the item that your pointer is on. In other words, if your pointer is on a file's icon, clicking once will select it. If the pointer is on a button or link, clicking once will activate it. If your pointer is on a text field, clicking once highlights the field and allows you to start typing text in it.
If you want to open a file, folder, or application, click your mouse button or trackpad twice. This is known as double-clicking. In general, you'll need to double-click items if you want to open them from a Finder window or the desktop. The exception to this is opening stuff from the Dock—just click once on an icon in the Dock to open it.