If you are reading for general interest, you often only need to understand or remember the main points. You don't always need to read or remember specific details.
Here are two examples of when you may only need to read for the main ideas. Click on each example to find out more.
You might want to see what the main features of the car are, but at this stage you do not need to read in detail about what all the switches do, how to operate them, etc.
You just need to know enough about the job to decide if it is worth telling your friend about it. If they are interested they can check the details and decide whether to apply.