Transfer button: When printing process color separations, this button allows you to compensate for dot gain and loss from inside the Print dialog box. However, since dot gain is taken into account and dealt with appropriately when configuring the color settings from the Edit menu, this is best left at its defaults.
Transparency: When an area of an image is “erased to transparency," there is a checkered background showing. There is nothing on that part of the image.
Trim: The Image>Trim command automatically trims an image (which is like cropping) based on attributes you specify in the Trim dialog box. This trimming can be based on transparent pixels in the image, the top-left pixel color, or the bottom-right pixel color. With that choice made, the trimming can be done from the top, bottom, left, or right sides of the image or a combination of these.
Tsume: Reduces the space around a character. The character is not squeezed or stretched as a result of this action, only resized.
TWAIN: A proper name that is often followed by the words compliant driver or compliant application. TWAIN-compliant hardware, such as scanners, allows you to use your scanner and scan an image from various applications that are also TWAIN compliant. (This is what makes the File>Import command work.) Other hardware can be TWAIN compliant too, such as digital cameras and virtual devices, explaining why some digital cameras, scanners, and similar hardware work from inside Photoshop and others don’t.
Type Mask tools: Allows you to create a selection in the form of typed letters. These selections can be moved, copied, or filled with color just like any other selection can. Type selections are best created on a normal image layer and not a type layer, since the type is created from the underlying image.
Type tools: There are four Type tools: the Vertical Type tool, Horizontal Type tool, Vertical Mask Type tool, and Horizontal Mask Type tool. These tools are used to add words to an image. With a Type tool selected, you can set options for font, size, color, alignment, and more.