Hyperthreading is Intel’s proprietary technology where a single processor-core can work on not one, but multiple, sequences of instructions in parallel. It is a hardware-level feature done by efficiently dividing the tasks by the processor so it can execute multiple threads simultaneously in each core.
In other words, hyperthreading will create logical/virtual cores for the operating system. So a quad-core will be perceived as an 8 core processor by the operating system. Each core can independently interrupt or execute the instructions.
Hyperthreading can efficiently divide a physical into two logical cores by the time of writing, and the processing is performed on two threads at the same time. However, hyperthreading is only beneficial for performing certain tasks.