For the vast majority of properly-designed Macintosh applications, deploying to the /Applications folder is not necessary.
However, it is considered a best practice. When someone is working on your Mac (EG, one of the employees at the Apple Genius Bar), having your applications located in a single, sane, system-recognized place makes life considerably easier for them. It's also plausible that a poorly-designed app may misbehave when not installed to /Applications, although I've not typically found that to be the case. Some newer apps are detecting when they're launched from somewhere other than /Applications (typically the .DMG from their download) and automatically installing themselves correctly.
If you want to quickly access an application which is deployed in the /Applications folder (or you simply don't want to dig through a zillion entries to find the app you want), I recommend using Aliases (Command-L in Finder), and placing the Alias wherever you like. For example, I use Dock folders ("Stacks") full of Aliases for all my app-launching needs, with folders for Development, Productivity, Multimedia, Games, Internet, etc.
Whenever someone asks a question such as this (or, alternatively in the Windows world, "do I need to use the 'My Documents' folder for my files"), I always ask back: Do you have a genuine, critical need not to do so? One which isn't addressed by the in-box aliasing ("shortcut" in Windows) mechanism?
dmg
files are disk images, like a downloadable thumb drive or CD. You double-click them, they get mounted ("inserted"), and you can view their contents.
Applications either are distributed as an installer (very few, mostly big name software from Apple, Adobe, or system-related software such as VMware Fusion), or directly as application bundles.
You start installers by double-clicking, then follow the steps you're presented. Applications are usually installed to /Applications
.
You "install" application bundles by copying them to a convenient location (e.g. /Applications
or ~/Applications
) and that's it. This is what quite a few applications (e.g. Adium) relate to in their disk image design:
Open source, Linux and UNIX related applications are available via one of the unofficial package managers Fink, MacPorts and Homebrew. Which you use (or even none at all, if there's no need) is up to you.
Since a few days ago, there's also the Mac App Store, a concept that debuted on iPhone and iPad. It includes auto-update functionality, and very many applications are also available on there.
Uninstallation of software not installed using Mac App Store or one of the package managers is an "unsolved problem". You can just delete the application bundle in /Applications or
~/Applications` and be done. There's no "registry" to keep clean, and the tiny personal preferences files don't hurt.
Some applications dump quite a bit of data in your ~/Library
(especially Application Support
) but there are solutions once disk space is tight. See the bottom of my answer regarding information what is stored where in your library folder, or this answer regarding a completely different topic, but might be helpful anyway.
Otherwise, I wouldn't care much about that. I created my user profile back in 2005, moved it across three machines, and it still runs quite well. I had several hundred applications installed and uninstalled during that time period, and can't complain about speed. As I said, there is no "registry".
Some "applications" (e.g. Witch mentioned further below) are actually preference panes (extensions to the System Preferences application), or widgets for your Dashboard. You usually recognize them by their icon. Simply install by double-clicking.
You launch/open applications by double-clicking them, or using open -a ApplicationName
in the Terminal. They are located in /Applications
or one of its subdirectories. Check the Finder's Go menu for keyboard shortcuts there.
You can dran applications to the Dock to keep them there (similar to pinning in Windows 7 task bar). Drag them off the Dock again to remove them. The Dock displays both "pinned" and running applications, so dragging running applications off the Dock does not have an effect immediately.
You can also drag them to the Finder sidebar, to launch them from there, or to the Finder toolbar. There are other applications available, such as Overflow that attempt to help you launch applications.
A popular alternative is to use an application launcher like Quicksilver, Launchbar, or Alfred for launching applications.
You can quit any application by pressing Cmd-Q
or selecting Quit in its application menu (the menu opened by clicking the application name in the menu bar). You can even quit them from the application switcher you get by pressing Cmd-Tab
: Keep Cmd
down to keep the switcher open, and press q
-- the selected app will attempt to quit. Alternatively, you can quit applications by right-clicking or click-and-holding their Dock icon until a menu appears.
Frozen applications can be terminated in the same Dock menu by pressing Option
and selecting the Force Quit
menu item that appears. Alternatively, pressing Cmd-Option-Escape
opens the Force Quit Applications window, where you also can quit frozen applications.
Some applications quit when you close their last window, but it doesn't always make sense:
- why should a Mail application quit when you don't want to view it, but it can notify you about incoming mail?
- Why should an editor or authoring tool that takes several seconds to launch quit, because you want to work on another document and you close the previous one?
Good to know:
Documents and applications are separate in Mac OS X: Any application runs only once (there are workarounds, such as the open
command-line program), and each instance supports multiple documents. That's why the application switcher only displays applications, not documents. Use LightSwitchX or Witch if you don't like this.
For general information about using your new Mac, you can start by reading Mac 101 from Apple.
There are some books available, e.g. the "Missing Manual" series. Just check out Amazon and read a few reviews.
TidBITS offers ebooks on select topics, e.g. backups, in their "Taking Control" series.
This site has tons of information about Mac OS X, and quite a few users who are regulars on Mac-related topics. You could search this site specifically for some information, if you don't want to read a book from cover to cover.
Some of Apple's developer documentation might be interesting for users as well. This and this are guides for developers where to put their applications' files.
Best Answer
DMG stands for Apple Disk Image. These are treated like a Volume of their own, but one that's contained in that file. Volumes on a Mac are basically any physical or virtual disk that can be mounted permanently or temporarily. The hard drive icon you see on your desktop (probably Macintosh HD unless you renamed it) is a volume. You can clone one volume to another easily, whether it be physical or virtual. This is one of the features that makes a Mac so powerful.
These volumes are "mounted" or "unmounted" on the Mac OS. This is similar to Windows in that when a removable drive is plugged it, it's automatically assigned a drive letter (E:)... in other words, it's mounted. When you "safely remove" it, you're unmounting it. You must always unmount a drive on the Mac OS before removing it, whether it be physical or virtual.
A DMG is similar to any other compressed file, like ZIP in Windows, but more powerful on the Mac OS. The DMG is a self contained volume formated HFS+ that retains file system attributes that are important. These are called resource forks and are usually invisible to Mac users. If you've ever copied a file from your Mac HD onto a FAT32 thumb drive, then plugged that drive into a Windows box and seen those pesky "._name" files, those are resource forks. They're important to a Mac as they contain metadata pertaining to the file itself.
When you download a disk image containing an Application, the app should be copied to your Applications folder before running it. This is because most disk images are read-only, and running it from inside the disk image can produce undesirable results.
Some Applications come in a package which are handled by the Macintosh Installer. These usually need to write system setting files that require administrative access and will prompt you for your password. Make sure you know where a package came from before giving it your administrative password.
The application, when launched, will create a few files that it needs in your Library folder in your Users directory (your username... looks like a Home icon in Finder). Settings you change while using the application are stored into these files, so if you "uninstall" the application by moving it into the trash, then re-install it later, those settings are retained. This can be a good or bad thing, depending on what you want. If you want to completely remove an application along with all of it's settings pertaining to you and/or the system, first see if the Application came with an uninstaller. This might be in the application folder itself or in Utilities (Adobe is notorious for having it's own uninstallers). Usually, if an application was installed via Macintosh Installer, it will have it's own uninstaller or you can visit the company website for instructions on how to remove it. If it was a standalone application and you want to completely remove everything related to it, you can use a great free program such as AppCleaner to do this.
Hope that helps some. Enjoy Mac!