• Concurrency: the art of doing several things at the same time
• Implementing patterns
• race condition, synchronization, volatility
• visibility, false sharing, happens-before

Accessing data concurrently may lead to issue!

It means that two different threads are trying to read and write the same variable at the same time.

Prevents a block of code to be executed by more than one thread at the same time.

A deadlock is a situation where a thread ${T_1} holds a key needed by a thread ${T_2}, and the ${T_2} holds the key needed by ${T_1}.

1. create an instance of Runnable
2. pass it to the constructor of the Thread class
3. call start() method of this thread object