I just found that there is a apt command that you can use directly:

 $sudo apt 

 apt 1.0.1ubuntu2 for amd64 compiled on Apr 10 2014 13:03:39

 Usage: apt [options] command



 CLI for apt.

 Basic commands: 

  list - list packages based on package names

  search - search in package descriptions

  show - show package details

  update - update list of available packages

  install - install packages

  remove  - remove packages

  upgrade - upgrade the system by installing/upgrading packages

  full-upgrade - upgrade the system by removing/installing/upgrading packages

  edit-sources - edit the source information file

With similar syntax to apt-get. And it offers some coloring in the CLI interface. So I want to know if there are some major difference between apt and apt-* commands? Why do people seem to post commands as apt-get install and apt-cache search when they don' t need the additional options apt-* commands provide, while apt is shorter with all the similar functionality with additional coloring, and in my opinion, better output format? Is it only habit?

I see in the manual pages that apt is for end-users while other low-level commands are for scripts. So why is everyone posting those low-level commands instead of the more user-friendly high level command?