Style

• command
  anything you have to type litteraly
• argument
  substitute an actual value
• directory
  the name of a directory
• file
  the name of a file
• program
  the name of a program
• matrix
  the representation oa a matrix
• vector
  the representation of a vector
• symbol
  a symbol
• Button press
  the name of a button
• 
  

  a script
  for example
    commands to run in a shell
    input for a program

• 
  

  output
  for example
    sample output from a program