When you execute something synchronously, you wait for it to finish before moving on to another task. When you execute something asynchronously, you can move on to another task before it finishes. That being said, in the context of computers this translates into executing a process or task on another "thread." A thread is a series of commands (a block of code) that exists as a unit of work. The operating system can manage multiple threads and assign a thread a piece ("slice") of processor time before switching to another thread to give it a turn to do some work. At its core (pardon the pun), a processor can simply execute a command, it has no concept of doing two things at one time. The operating system simulates this by allocating slices of time to different threads. Now, if you introduce multiple cores/processors into the mix, then things CAN actually happen at the same time. The operating system can allocate time to one thread on the first processor, then a...
![The first confirmed sample of water from the subsurface Lake Vostok (at a depth of 4000 meters) in Antarctica has been retrieved. The water has been isolated from the outside world for at least 100,000 years!
Read more: http://bit.ly/WsXuPg by Caleb Scharf @[22297920245:274:Scientific American magazine] blogs.](https://fbcdn-sphotos-d-a.akamaihd.net/hphotos-ak-snc7/s480x480/304114_10151440884062518_1877538948_n.jpg)
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