Search this board for "neighborhood" (all these words) and "impposter" (author) for many previous posts in reply to the "where to stay" kinds of Qs. The most recent one is from February:
http://www.theeroticreview.com/discussion-boards/boston-9/boston-neighborhood-map-221455
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In general, Boston has those that prefer downtown locations (very easy to get around downtown Boston: foot, subway ("The T"), cab / uber, but not so easy to park) and those that prefer the suburban locations. For those driving, suburban "Waltham" is at the intersection of I90 ("Mass Pike," the major east-west in/out bound highway) and I95 ("Route 128," the major loop around Boston from all the way north to all the way south). But there is also Newton, Woburn, etc., along I95 = 128.  
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If this is your first trip to Boston, you might prefer to stay in the city ("downtown") so you can see the sights and hit the more famous attractions. The neighborhood map shows some of the major neighborhoods. "Back Bay" is very popular with lots of hotel choices. Not shown on this map is "Copley Square" which a smaller area within Back Bay. Same deal: lots of hotels right around Copley Square, also just known as "Copley."  
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There is only one Copley so when you say "Copley" it means the Copley Square area. However, there is "South Boston" and the "South End." Even though adjacent, they are very different. Don't get them confused! Likewise, Roxbury and West Roxbury.
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