what is a picker?

A picker is a tool used to manually select and move objects within a computer's graphical user interface (GUI). Pickers are often seen in applications such as Adobe Photoshop and Illustrator, where the tool allows users to select an area of an image or text that they wish to modify.

When using a picker, the object being selected is displayed within the GUI surrounded by a movable rectangular frame known as a "selection box" or "marching ants." The box will be highlighted in red or blue, depending on which version of the software is being used. The size of the selection box can be adjusted either manually using the cursor keys on the mouse or keyboard, or automatically using numerical values entered in a dialog box.

Traditionally, pickers were used primarily for selecting specific areas within images such as faces, trees and buildings at different levels of magnification. However, newer versions of popular software packages also include options that allow pickers to be used for selecting other types of elements like typeface characters and layers of various objects.

Pickers are also commonly found in desktop publishing software packages like MS Publisher and InDesign and page layout programs which enable users to manipulate text flow around variable shapes such as circles and arrows. Using pickers makes it so much easier for graphical designers to select specific elements within their page layout quickly and accurately for precise manipulation.