this link might help you understand how the two work together:
multisite is just activated by a setting in your wordpress config file it can be done before or after buddypress but if you are starting from scratch id probably do the multisite first, then add any plugins.
The difference is in the scale and the level of complexity.
buddypress + WordPress on a single site is relatively simple to setup
wheras Buddypress+ WordPress Multisite is more complex and requires additional hosting resources
The functionality difference is on a single site install your users will be posting to a single blog whereas on a multisite instaall each user would have their own blog to post to.
If you are just seting up the site then my advice would be keep it simple and go for a single site WordPress+Buddypress setup
I’m a great believer in keeping things simple,and WordPress Multisite creates an additional layer of complexity which you probably do not require in initially.
Thank you so much @ubernaut and @DennisBarkerCV for your insight and explaination.
I am currently setting up the theme with just basic stuff and will install BP plugin soon.
Since I am not a developer or programmer by any means, so I guess I should keep things simple in the beginning.
I will evaluate later on in few months if I want to go with MultiSite route when I have some experience with WP/BP.
Btw, one more question: I came across this plugin today and it lets people post article from their profile. This way users can still write their unique posts even though I there is no MultiSite : https://wordpress.org/plugins/social-articles/
Is it a good idea to install this along with BP or it can cause confusion among users if BP already lets users post articles.
Thank you again for your help.
never used that before, sorry. the only reason to add multisite is if you want you users to be able to create their own semi-independent blogs/sites. if you only want them to be able to create posts you have a lot of options.
Yes, simple buddypress posting and sharing in the beginning. Will evaluate multisite needs as gain more experience with BP.