What is the OPTIONS BAR?
Directly linked to the Toolbar is Photoshop's Options Bar. The Options Bar displays options for whichever tool we've selected in the Toolbar. You'll find the Options Bar along the top of the interface, just above the document window. Here we see that, because I currently have the Rectangular Marquee Tool selected, the Options Bar is showing options for the Rectangular Marquee Tool:
Options for the selected tool appear in the Options Bar.
If I choose a different tool from the Toolbar, like the Crop Tool:
Then the options in the Options Bar change. Instead of seeing options for the Rectangular Marquee Tool, we're now seeing options for the Crop Tool:
The Options Bar updates each time a new tool is selected.