Action files: Recorded actions that can include adding text effects, image effects, and production actions, such as changing a custom RGB file to grayscale or saving a file as a JPEG, and will increase the efficiency in which you perform oft-repeated tasks.
Actions palette: Lets you record, play, edit, and delete specific actions or load action files.
Additional options: These are available when a pop-up palette is opened and denoted by a right arrow located in the top-right corner of the palette. Clicking on this arrow brings up the additional options.
Airbrush: Simulates traditional airbrush techniques by gradually adding paint similar to a spray paint gun or a spray paint can. The airbrush icon is located on the options bar when a brush is selected.
Align: Allows you to align layers or selections within an image. There are several ways to align objects: top, vertical center, left, horizontal center, and right.
Aligned: Use when repairing flaws in images (such as when using the Healing Brush or Clone Stamp tool). Place a check in the Align box if you need to release the mouse button while working and still keep the sampling point; sampled pixels are thus applied continuously. Uncheck the box to apply the pixels from the original sampling point each time. Aligning can also mean to left align text, center text, or right align text.
Alpha channel: A spot color channel in the Channels palette that you create using the Color Range tool.
Anchor point: As lines and curves are drawn using the Pen tool, anchor points are created that define the line, its endpoints, and its curves. Anchor points can be added or deleted from a shape, and they can be edited.
Angle: Controls the angle of the brush stroke. Angling creates a calligraphic look.
Anti-Aliased/Anti-aliasing: Anti-aliasing is the process of smoothing edges around a selection. It differs from feathering in that it does not blur the edges but instead softens them by blending the colors of the outer pixels with the background pixels. This results in no loss of detail. You must choose anti-aliasing before selecting; it cannot be added after a selection has been made.
Art History Brush: Allows you to change an image to make it look like some other type of artwork—artwork that is older, such as impressionist artwork, an oil painting, or a watercolor. These changes are unlike filters and similar tools because they allow you to brush over only part of the image to make the changes and do not apply the change to the entire image or layer.
Auto Color: Adjusts the colors in an image by searching the image for shadows, midtones, and highlights instead of basing those adjustments on the histogram settings. Auto Color is located at Image>Adjustments.
Auto Contrast: This command adjusts the contrast of an image but does not repair color-related problems such as colorcasts. By enhancing the contrast of the image, whites appear whiter and blacks appear blacker, and everything in between changes accordingly.
Auto Erase: Available with the Pencil tool, checking this box allows you to paint the background color over areas of foreground color. This, in essence, erases what has been previously drawn with the foreground color.
Auto Levels: A command in the Image>Adjustments menu that sets highlights and shadows in an image by defining a black point and a white point based on the majority of colors in the image and the lightest and darkest points. With the black and white points set, it configures the intermediate colors accordingly.
Auto Select Layer: Automatically selects the layer you intend to work with as determined by where you click with the mouse.