You can perform actions in cow that allow you to interact or communicate with objects around you.
The default action is say so if you dont specify any command you will say what you type.
Type in the words hello bob, how are you today? and if bob is logged on and in the same location as you, bob will see what you say.
If Bob is in a different location to you can shout, hello bob or say hello bob loudly.
Anything you shout or do loudly is heard by everyone currently logged on.
Other action commands like watch, think, sing etc.. will show others in your location what you are doing.
Most can be use as the word on their own laugh or with extra text laugh what are you doing there!?!
Some commands will have an effect on an object. catch will make you hold the object, zap will push an object off anything it is currenly on or beside (players get zapped out of the room).
Try this create a box. create an apple. put the apple on the box. zap the apple The apple first show as being on the box, then it is zapped off it.
readall book of actions to see all of these commands