Chakra is the energy that is essential for even the most basic technique. after molding chakra, it is possible to manipulate it to perform feats that are though to be impossible, such as breathing fie, walking on water, and creating illusions. Chakra can be use in five affinities, fire, water, earth, lightning, and wind. Some skilled users can mix the elements, creating a Kekkei genkai or Kekkei Tota.
Ninjutsu is the creation of any technique, and relies on chakra and hand seals. Ninjutsu can be used for many different purposes, such as using the elements, escaping binds, or transforming the user.
Shinobi is another word for ninja. Most shinobi come from a village, some under their families' clan. Shinobi perform various missions for a fee. Missions can include assassinations, manual labor, gathering secret info, retrieving stolen items, etc. When war strikes, the shinobi from each land gather together to defend their homelands and villages.
All three of things relate to each other greatly. Without chakra, there will be no ninjutsu. And a shinobi is needed to create the ninjutsu. If one of the 3 things listed are absent, the others will fail without a doubt.
Does this answer suffice, Senpai?