Is wall street just a street or a walk way?
Well is a network of eight-block-long street running roughly northwest to southeast from Broadway to South Street, at the East River, in the Financial District of Lower Manhattan in New York City.
I learnt its a financial hub, is that correct?
Over the years ,the term has become a metonym for the financial markets of the United States as a whole, the American financial services industry 
So what major activities do they do there?
Its how to the economically powerful city and the leading financial center of the world, and the city is home to the world's two largest stock exchanges 
What's the New York stock exchanges about?
Its an American stock exchange located at 11 Wall Street, Lower Manhattan, New York City, New York.
Any other info?
Also,Several other major exchanges have or had headquarters in the Wall Street area, including the New York Mercantile Exchange, the New York Board of Trade,