Very broadly, the great variety of British place names is a product of the islands' history of invasion. The names we use today are evolutions or distortions of older names that were often originally in other languages, not least Anglo-Saxon, Norwegian, Danish, and French.

This can be incredibly helpful for historians, especially those studying periods for which there is little or no written record. Scholars such as FT Wainwright have used place-name evidence to trace the pattern of Scandinavian settlement in Lancashire or the extent of the advance of Saxon settlement in the British south-west.

Suffixes are the biggest giveaway here. Common ones derived from Anglo-Saxon include

-ham, a homestead or village

-leigh, -ley, a clearing

-burh, -bury or -borough, a fortified town

-ford, a river crossing

-stowe, a meeting place

Names that betray Viking settlement include

-thorpe, -thwaite, a hamlet or secondary settlement

-kirk, a place with a church

-wick, a bay or creek

-holme, an island

In the case of your Great Snoring (and I gather there's also a Little Snoring), the original place name would appear to have been the Anglo-Saxon "Sneare-" (meaning snare, or possibly noose), and the "ing" (which also appears in places such as "Hastings", of course) is a contraction of the Saxon "ingas", meaning "the people of", and denoting a group living in a specific place under a common leader. Over time, and with the evolution of the English language itself, "Sneareingas", meaning the spot settled by "the people of the place of the snare," became "Snoring", and the "Great" and "Little" probably distinguishes between larger and smaller settlements in the same area (though it might also refer to their relative geographical settings).

There are several societies, most famously the English Place-Name Society based at the University of Nottingham, dedicated to getting to the bottom of problems such as this.