Earlier quoted context omitted.
Revenue: sales recorded. This might or might not represent cash coming through the door in this quarter, but it represents that there is an agreement for cash and goods/services to change hands. Operating income: Money left over after you subtract the costs of operating the business and making the sale. In a manufacturing firm, for example, you would subtract the cost of the materials in the goods sold. For Google th…
"Revenue: sales recorded." Small clarification, this is sales recognized. For example, if your customer signs a 2 year service agreement at the start of a quarter, the revenue reported that quarter should be 1/8th of the total contract amount (assuming you are recognizing revenue at a flat rate).
For those following along, spending some time with an introductory financial accounting book or textbook is a very useful way to understand a lot of business behaviour. I took a 101-level accounting course during my computer science degree and it has proved to be a very useful thing to have learned about.