Hi friend,

Quartz Scheduler :

Quartz is a full-featured, open source job scheduling framework written entirely in Java.It can be integrated with, or used along side virtually any J2EE or J2SE application - from the smallest stand-alone application to the largest e-commerce system. Job scheduler is a system that
is responsible for executing other software components when a pre-determined (scheduled) time arrives.Quartz is quite flexible. It contains multiple usage paradigms that can be used separately or together
to achieve the desired behavior. And it enable you to write the code in the way that seems most natural to your project.Quartz is a fault-tolerant, and can persist your scheduled jobs between system shutdown and restarts.Quartz is very useful for simply executing certain system process on given schedules.

Thread :

A thread is a lightweight process which exist within a program and executed to perform a special task. Several threads of execution may be associated with a single process. Thus a process that has only one thread is referred to as a single-threaded process, while a process with multiple threads is referred to as a multi-threaded process.

In Java Programming language, thread is a sequential path of code execution within a program. Each thread has its own local variables, program counter and lifetime. In single threaded runtime environment, operations are executes sequentially i.e. next operation can execute only when the previous one is complete. It exists in a common memory space and can share both data and code of a program. Threading concept is very important in Java through which we can increase the speed of any application. You can see diagram shown below in which a thread is executed along with its several operations with in a single process.

For read more information,Examples and Tutorials on Quartz and Thread visit to :

http://www.roseindia.net/quartz/

http://www.roseindia.net/java/thread/

Thanks