Definition - What does Lightweight Thread mean?
A lightweight thread is a computer program process, normally a user thread, that can share address space and resources with other threads, reducing context switching time during execution.
Techopedia explains Lightweight Thread
Threads are typically compared in terms of processing time. For example, a lightweight thread is a thread that takes less processing time, whereas a heavyweight thread is a thread that requires more processing time. Thread processing time is also contingent on the language used for thread implementation. For example, it may be more efficient to use C# to implement a program containing multiple threads.
Modern operating systems, like Mac, allow for more than a single thread in the same address space, reducing switching time between threads. However, this does not make use of multithreading benefits.