In Mac OS X, what is the Info window, and how do I use it?

In Mac OS X, the Info window provides information about documents, folders, volumes, applications, and other items. To open it, click an icon for which you want information. Then, when the icon darkens, from the File menu, select Get Info (Mac OS X 10.2.x and later) or Show Info (Mac OS X 10.1.x and earlier). The Info window has several different panes you can access by clicking the triangles next to their names (Mac OS X 10.2.x and later) or through the pop-up menu (Mac OS X 10.1.x and earlier). The panes and their functions are listed below.

Notes:

This document assumes you are viewing the information for a single file. However, if you select multiple icons in the Finder and open the Info window, you may view information about and make changes to the entire selection.
In Mac OS X 10.4 and later, the Info window displays information for multiple files differently. The Get Info option on the Finder File menu provides information individually for all of the documents, folders, volumes, applications, and other items selected. If you hold down the Option key on the keyboard while selecting Get Info from the Finder File menu, you'll see a combined summary of information about all of the documents, folders, volumes, applications, and other items selected.

The "General" or "General Information" pane

All icons have a pane containing general information. Its contents depend on the type of file or folder associated with the icon, but may include the following:

Kind: This tells you the type of item you are viewing. Documents will be identified by the application program that created them, if possible.
Where: This gives the folder structure describing where the item is on the disk.
Size: This tells you the amount of space the file or folder takes up on the disk. With folders and packages, this amount is the total of all enclosed files.
Created: This shows when the item was created.
Modified: This shows when the item was last modified.
Version: This lists the version of the item.
Format: This is reported for volumes (e.g., hard disks, removable media, network volumes, audio CDs, and video DVDs) and describes the kind of file system the volume uses.
Capacity: For volumes, this lists the total amount of space.
Available: For volumes, this lists the amount of unused space.
Used: For volumes, this lists the amount of space taken up by data.
Original: For aliases and links, this lists where the original file or folder is located.
Full Name: This is the name by which fonts will be displayed in applications.
Copyright: Frequently, fonts will have their copyright information listed in this field.
Comments: (Mac OS X 10.1.x and earlier only) This field shows any comments attached to the item.
Locked: If you select this checkbox, the document cannot be changed.
Stationery Pad: If you select this checkbox, when you open the document, the document will instead open a copy of itself.
Open in the Classic environment: If you select this checkbox, an application will launch in the Classic environment instead of as a Mac OS X-native application. Only certain Carbon applications will have this option available.

The "Name & Extension" pane

In Mac OS X 10.0.x, you can change the name of a file from any pane in the Info window. Beginning in Mac OS X 10.1, however, you can do this only in the "Name & Extension" pane. In 10.1 and higher, you can also use this pane to determine whether the Finder will display the file's extension or not.

The "Content index" pane

In Mac OS X 10.2.x, using the "Content index" pane, you can see whether a folder or volume has been indexed, and if so, on what date it was last indexed.

The "Application", "Open with application", or "Open with" pane

This pane is called "Application" in Mac OS X 10.0.x, "Open with application" in Mac OS X 10.1.x, and "Open with" in Mac OS X 10.2.x and later, and is available only with documents. You may use it to designate what application will open a document when you double-click it. You can also use this pane to change the opening application of all the other files on your computer that are of the same type and were created with the same application.

The "Preview" pane

For text and PDF files, as well as files in formats that QuickTime understands, the "Preview" pane will show you the file's contents.

The "Sharing & Permissions", "Ownership & Permissions", or "Privileges" pane

In this pane you can set the owner, group, and global access permissions of files, folders, and volumes. For folders, you can copy the access permissions to all enclosed items.

The "Languages" pane

In Mac OS 10.1 and later, with many applications you may add and remove language support from this pane of the Info window.

The "Memory" pane

For Classic applications, from this pane you may view and adjust the memory allocation settings.