Dear friend,
Others have explained in detail. You may please note that 'Loss of Pay' leave is not ordinarily granted. Only under special circumstances is such leave granted when an employee does not have any other leave, such as CL, EL, SL/ML, in the credit of their leave account. In some establishments, especially in Government/PSUs, it is known as 'Extraordinary' or 'LWP' leave. As it sounds, it is an authorized leave under special circumstances, such as on medical grounds or for higher studies, etc. Whether it will be considered for computing 'Continuous service' depends on one's leave policy and on such grounds.
When an employee is absent without approval of any kind of leave, they will be considered as absent and will earn no pay, apart from being subjected to disciplinary action. Many establishments' leave policies will define what 'Loss of Pay' leave is, under what circumstances it can be allowed, the maximum period that could be allowed, and other stipulations.