Economical Calender Help

Hi:

I want to know how to read economical calender?
What are the facts in economical calender?
What it tell us?

For example this is economical calender:

Eco Data 7/27/07 - Forex Trading, Currency Forecast, FX Trading Signal, Forex Training Course, Education, Tutorial, FX Book, Forex ebook, Learn to Trade Forex, FX Guide, Pivot Points, Currency Rates, Forex Secret, Forex Brokers, Currency Trading Syst

Here are many fields like:
Ccy | Events | Actual | Consensus | Previous | Revised

What are these fields?

Thanks
Burhan Khan