Often referred to as the Contextual Option Bar, the Option Toolbar contains tools and settings to control and fine-tune each item within the tool palette. Option controls and other function will be displayed in context with any currently active tool.
This toolbar can also be move from the top of the interface and docked anywhere on screen if you prefer. To do so, simply click and drag on the tab to the far left of the bar. To reconnect it to the top of the interface, just drop it into position. Personally, I find that the default top position is best.