Authenticate for Everything

Just now, when I try to uninstall a program or move it to trash, I get a window saying that Finder wants me to authenticate this task. This never happens before. Even when I want to copy/paste a program for installation to the applications folder, the "paste" in the apps folder is greyed out. Even if I drag a program to the App folder icon, I get a window having to authenticate. Why all this authenticating, I prefer to authenticate as little as possible, how can I change this? I am a fairly new Mac user, so please make your reply easy to follow. Thanks, Ken.