Skimming:
Skimming is looking quickly through a text to get the general idea of a subject. For example some people will skim through a newspaper to see which articles interests them or to find out the general idea of a reading. In an exam situation you may skim through a reading to find the parts that you need to study carefully
Skimming helps you to save time
Scanning:
Scanning is when you quickly look through an article looking for specific information e.g. names, facts or figures. For example you may scan through a phone directory looking for a specific telephone number.
Scanning helps you to quickly locate information without having to read through everything
Now try out the exercises
Independent Exercise for Skimming and Scanning Maker of Animated GIFs Waits for Offbeat Moments Skimming and Scanning Reading Skimming and Scanning ex 1