Answers to Quora Questions by Yair Davidiy (22 August 2017, 30 Av, 5777)
What are the largest differences between orthodox and hasidic Jews?
https://www.quora.com/What-are-the-largest-differences-between-orthodox-and-hasidic-Jews/answer/Yair-Davidiy
(10 April, 2018, 25 Nisan, 5778)
Strictly speaking Hasidim are a branch of Orthodox Jewry. The questioner apparently intends to inquire as to the difference between Hasidim and the other Orthodox. The Orthodox Jews may be divided into different groupings: One has Modern Orthodox and Ultra-Orthodox (Hareidim), as well as (mainly in Israel) National Religious, and then there are the Hasidim. Modern Orthodox and National Religious roughly speaking may be considered modernized offshoots of the non-Hasidic Ultra-Orthodox. These are also known as "Litvaks," i.e. Lithuanians after the place whose religious centers most influenced them.
What is the difference between the Litvak Ultra-Orthodox and the Hasidim?
Hasidim put more emphasis on a leading "Rabbi." The Rabbi is a charismatic personality or the offspring of one. It goes in the family though occasionally new "Rabbis" do appear. Hasidim are more communally orientated and inter-twined with each other. They have more communal gatherings, talks from the Rabbi, assemblies, etc. They often emphasize prayer over learning. They tend to often favor strict rulings for the sake of it. Litvaks may also have that tendency but overall are more rational.
Litvaks stress the importance of learning for its own sake as well as in order to know what should be done. Litvaks and Hasidim these days may overlap. They co-operate in dealing with external forces. Hasidim may learn in Litvak institutions though Litvaks will seldom learn in Hasidic ones. The two groups seldom intermarry with each other. Litvak institutions in Israel generally teach in Hebrew whereas Hasidic ones usually use Yiddish.
In Israel most of the Ultra-Orthodox Sephardim have recently attached themselves to the Litvaks and become part of them. This may seem strange to an outsider but in general it works. On the other hand, one also has Chabad Hasidim (Lubavitch) who in many ways are considered a part of the National Religious Orthodox group who in turn often adopt Hasidic teachings. Chabad emphasizes outreach and attracts Jews from all over including many from North African Jewish communities such as those now in France and Israel.
This is an interesting and complex subject. Books have been written about it but much remains to be said.