*Upon having foreign hands placed upon their bodies, both brothers immediately cringe*
Saki: Why? Why would you scare us? >_<
Urasan: Relax brother, it would appear our sensei has arrived.
Urasan: Sensei, we want to learn about ninjutsu because it is incredibly versatile and a major tenet of being a shinobi.
Urasan: It can be of great assistance whilst on the field, for assaults, reconnaissance, or restraining.
Saki: Ninjutsu can involve the manipulation of ninja tools, standard chakra with nature/shape manipulation, and barriers.
Saki: Even in the academy, aspiring shinobi need to demonstrate several simple techniques that are labeled as ninjutsu.
Known users from the manga include TenTen (her scrolls), Naruto (spamming of Shadow Clones and Rasengan).
The use of barriers has been demonstrated by the Sound Four, Jiraiya, and the Edo Hokages.
Saki: Discussing the strengths and weaknesses of general ninjutsu isn't really easy...
Urasan: Given the versatility of ninjutsu, there is no universal weakness to them.
Saki: Each jutsu, seemingly, has its own strengths and weaknesses in accordance with the nature of the specific jutsu.
Urasan: The only prevalent downside to general ninjutsu is that the user often relies upon their supply of tools.
Urasan: Even then, that isn't necessarily applicable to all techniques classified as general ninjutsu.
Saki: Perhaps you could shed some light on the general strengths and weaknesses, sensei?