You are completely fine, Sensai. I am only grateful to be receiving training! ^_^
___________________________________________________________________________________
Flash bombs are primarily used as red herrings. Diversions used to distract the enemy away from potentially life endangering activities. This can be used on the opponent, or on one's self. After use, a blinding light is cast within the immediate area, making normal eyes, Sharingan, and Rinnegan completely useless, considering all three are connected to the optic nerve, which operates based on light alone. Although this effect sounds incising, it only last a short amount of time, so if you want to accomplish something, you better do it fast. This is effective in scenarios where you want to lose sight of your enemy, allowing your to escape to be undetected. This is, of course, unless you are part of the Nara Clan, who would utilize this to create shadows to further their advantage.
_____________________________________________________________________________________
Smoke bombs have the same effect, but are slower about it than flash bombs. They generally conceal the location of whomever it is cast upon, but that is not to say that they are to be solely used for personal gain. The gas/smoke that is concealed could be poisonous, if used by a medical ninja, or if constructed correctly could be used for sleep agents.