1. What are the London, New York, Tokyo and Sydney sessions?
The Forex market operates 24 hours a day, Monday to Friday, because different financial centres around the world open and close at different times.
Sydney Session — starts the trading week and is generally quieter.
Tokyo Session — Asian trading session; currencies such as JPY can be more active.
London Session — one of the busiest sessions, with high trading activity.
New York Session — another very active session, especially for USD pairs.
There are periods when two sessions are open at the same time. These are called overlaps, and they can have more trading activity and volatility.
Simply: Forex sessions are different periods when major financial markets around the world are open.