Best way to uninstall programs or apps
First, don’t install a program unless you know how to uninstall it!!! The best way to uninstall is to contact the developers site for uninstall instructions, especially if the software required an Admin password to install. This is because it might have placed "hooks" into the operating system so if you simply drag the application icon you see in their Applications or Utilities folder to the Trash, leftover parts may cause a security or stability issue later causing your MacBook to boot to a "Gray Screen Issue" and remain stuck, causing the need to reimage or reset your device. Apps installed from the AppStore: If you have installed an App from the Appstore and you are a student, the only way those Apps can be removed is by entering an Admin ID and Password. This means you must go to the Help Desk to have these removed. If you have downloaded an App from a website and run it from a flash drive or from your desktop, you should be able to simply drag it to the trash to remove it. However, be aware that it may have run an installation program that put hooks into the operating system which may cause the need for your MacBook to be reimaged in order to completely remove it.
Self contained programs/apps: If you just dragged the program into the Applications folder to install it, usually its fine to drag the application icon located in the Applications or Applications > Utilities folder to the Trash. This only works for bundled or "self contained" programs meaning everything it pretty much requires is inside the Application icon which is really a hidden folder called a "package". These "self contained" programs or apps can be run from just about anywhere they are placed, and therefore removed by just dragging them to the trash.
Keep your Downloads folder clear: It is not advised to keep downloaded programs in the Downloads folder, rather to keep this clear at all times except during a known active download. Otherwise you could become victim of bad websites that will can cause a "driveby download" hoping you will click or run their software to infect your machine. The Downloads folder is not a storage place. If you want to keep a installer, put it someplace else in your User folders, like creating a folder called "Installers" or "Downloaded PDFs" and keeping them in your Utilities or Documents folders in your Home directory.
Installing programs or apps: When you click a link on a website to download, it appears in your Downloads folder which you open that and then the DMG volume that appears on the Desktop (if it has one) and doublelclick the installer (if it says it is) or drag the self contained program to your Applications or Applications > Utilities folder.
Then from there you drag it's icon to the Dock to make a "Alias" or shortcut so you don't have to dig inside the Applications folder to find it. Click on the Dock Alias to launch the program.
Installers are not usually kept on the Dock, rather once the program is installed the Installer is either Trashed or saved someplace else out of the Downloads folder to keep it clear.
Gatekeeper: For our Macbooks, Apple installed restrictions on where you can download and install software onto your machine. So if you go to a website and see something you like to install, Apple will prevent you from running the program and/or installer. The default security settings in your System Preferences > Security > General for downloads is set by default for "AppStore" and "Apple signed developers" only.
Warning! Contrary to the popular belief saying "If you don't give it an Admin password it can't do anything" is not entirely true. Simply running a malicious program in any user account can cause damage, it just can't as quickly gain root access to do the most damage right away, it certainly can encrypt your files or delete them, or install a keystroke logger and communicate that over the Internet, alter other applications and install a bigger payload of itself later.
The Dock: The Dock doesn't contain real programs, just “Aliases" or Windows users call "Shortcuts" which direct to the actual program, file or folders located elsewhere. To show the location of the real item in the Dock, right click and select Open > Show in Finder. The item there is the real thing, that's what is dragged to the Trash to delete (then Finder > Empty Trash to permanently delete it).
To delete the icon off the Dock, drag it's icon off onto the Desktop area and release, it does a puffy smoke thing and disappears.
A question mark icon in the Dock, means there is an Alias that doesn't know where the original file is located, so when clicked, it changes to a question mark like it's asking "Where is it?". To remove the question mark, simply drag it off the Dock onto the Desktop and release.
To place a mistakenly deleted Alias off the Dock back on or to place a new Alias on the Dock, locate it by clicking on the Smiley Face in the Dock to open a new Finder window, then navigate to it's actual location and drag it's original item into the Dock until it makes room and release. If you accidentally drop the icon on the Desktop, place it back in it's original location first, then attempt the Dock again.
Some items dragged to the Dock like folders and files will only fit on the Dock down near the Trash Can area, be careful not to place the original item into the Trash and then Finder > Empty Trash as it will then be gone!
Rather double click on the Trash Can to open it and drag the misplaced items back to their original location before trying the Dock Alias attempt again.
Sections of this KB are from article By ds store