What are the similarities and differences between Reiatsu and Chakra? What are the similarities and difference between Reiatsu from Bleach and Chakra from Naruto?

I've felt that they both are similar, like it's a part of the individuals' insides/spirit/soul and also it can be sensed from a distance. Generally, the higher the person's Reiatsu or Chakra levels, the stronger that person is. Another similarity is how Chakra and Reiatsu diminishes to zero while dying. However, there are some significant differences which don't make them the same thing with different names.

I want to know both the differences and the similarities between them.
Well, one of the main differences is most likely that chakra in Naruto seems to be a power exclusive to living things (like animals, plants and humans) while reiatsu in Bleach is more of a general form of energy (as all of Seireitei is made of reishi). Also, chakra can only be used through a medium (a body, tool etc.) while reishi can just be collected from outside and then used (like the way quincies collect reishi to form their arrows) 

Also, later in Naruto, Madara explains that


   chakra was not actually a power of humans. They "stole" it from the God Tree (神樹, Shinju), which then became the Ten-Tails. And the Sage of the Six Paths inherited chakra from his mother, defeated the Ten-Tails and gave chakra to living things as a mean to connect each others hearts. Only later they started to refuse to connection to each other, and instead train their own chakra to use it in battle. So while reiatsu is a ever present form of energy, chakra is more of a foreign power to humans 


In my personal opinion, I think that reiatsu is a symbol of "the power of one's Soul" while chakra is "the power of one's body".