Formation of spore inside the bacterium is called endosporulation as in bacilli .
No. Endosporulation is the process where bacteria encapsulates itself within an endospore - it's a form of protection against an extreme range environmental stressors. Sporulation on the other hand is the act of producing spores of the bacteria, and that IS a reproductive mechanism.
When a bacterium detects environmental conditions are becoming unfavourable it may start the process of endosporulation, which takes about eight hours. The DNA is replicated and a membrane wall known as a spore septum begins to form between it and the rest of the cell. The plasma membrane of the cell surrounds this wall and pinches off to leave a double membrane around the DNA, and the developing structure is now known as a forespore. Calcium dipicolinate is incorporated into the forespore during this time. Next the peptidoglycan cortex forms between the two layers and the bacterium adds a spore coat to the outside of the forespore. Sporulation is now complete, and the mature endospore will be released when the surrounding vegetative cell is degraded.
Spores are the dormant state of bacterial cell in this state they develop a protecting covering around the cell and all the cell organellis except nucleus and other esstional organallis for living get dissappear. The protective covering helps in enduring from harsh environment condition as low water aviability or high temp. etc.