If you have come across a tutorial or just someone on a forum who tells you to install something in Debian/Ubuntu that involves using apt-get, it is ok for you but when they tell you that you need to use a caret symbol (^) at the end, that’s where you become curious. What is even more weird is that when you search for the name of the package that the given command seems to install cannot be found using apt-cache search. e.g. You will see this used most often when someone tells you how to install LAMP server setup (Linux-Apache-MySQL-PHP) by using the command “sudo apt-get install lamp-server^”. If you miss the caret at the end or try to search for lamp-server, it just doesn’t work.
Well, the answer is that the caret symbol is a short form for performing a task that otherwise the program “tasksel” would have done with the given package name. tasksel is a program to ease the installation of commonly used things that go together for a particular use. e.g. In the above instance of LAMP, the four packages and their dependencies are always used together, so tasksel provides a sort of a meta-package or meta-task that can be run by the user with a single command and then tasksel will take it upon itself to install all of them and set them up correctly for your use. Now, apt-get provides a way to perform that same task by itself without you having to install tasksel first and all you have to do is to give that same package name to apt-get but just append a caret at the end to tell apt-get that it is a tasksel package/task identifier and not a regular package name in debian/ubuntu repositories.
Hope that clears things up :)