Haki is a mysterious power that is found in every living being in the world. It is not that different from the normal senses. However, most people do not notice it or fail to awaken it. The underlying concepts of Haki were introduced during the Sabaody Archipelago and Amazon Lily Arcs.[6] The concept was clearly explained by Rayleigh to Luffy at the start of the latter's training on Rusukaina Island.[3] Haki is dormant in every living person, but it's rare for most people to ever awaken that ability. Intense training can awaken it, as can extreme shock, such as with Coby during the Battle of Marineford[7]. Two known people (Aisa and Otohime) were born with the ability awakened, with no known training. Due to the fact that Haki originates from an individual's spirit and not their physical body, users are still capable of using it even if their spirit is transferred into another body.[8]
Chakra is similar people train to awaken it, but shock can (Haku was a civilian when his father tried to kill him), it can still be used in swapped bodies and the majority of humans in Nv are not Shinobi
Broadly speaking, there are two types of Haki available to everyone, given the proper training; however, there is a third type that only a certain group of "chosen ones" are said to possess.[2][3] In simple terms, Haki is an ability to sense spiritual energy (Kenbunshoku), use life force (Busoshoku) and overpower enemies (Haoshoku).
Chakra is made up of two base energies...Yin (Spiritual energy) and Yang (Physical or life force energy)
Types of Haki
Haki is separated into three categories, or "colors" (色 shoku?): Kenbunshoku Haki, which grants users a sixth sense of the world around them and limited precognitive abilities[41];
Chakra has sensors and Sasuke even did the foresight thing in the forest of death under the influence of Orochimaru's Killing intent...as a matter of fact...so did Kakashi, also against Orochimaru
Busoshoku Haki, which allows the user to use their spirit as armor to defend against attacks or to make their own attacks more potent;
Chakra can do the same...Infused into weapons, Kakuzu's earth spear Jutsu, hurt Suigestu,Shukaku, and trap spirits. Plus, various other reinforcements
Haoshoku Haki, a rare type of Haki only one in a million can use which grants the user the ability to overpower the will of others.
Genjutsu smh
Most people who can use Haki tend to have a type they are better at and as a result focus on that type. However, a person can improve their abilities with all the types of Haki, it just requires more work.[3] Furthermore, at least two types of Haki can also be used simultaneously.[42]
Same
Just seems to be equivalent to Chakra with Chakra being more versatile to be honest.