Can someone explain the difference between a porch and a terrace.?

Question:I've been referring to a 54 foot ong porch as a porch. Someone just corrected me and explained its a terrace. Is this an important distinction? I thought of a terrace as having a wall around it and a door leading to a room other than the front entrance hall.

Answers:
Main Entry: porch
Pronunciation: 'porch
Function: noun
Etymology: Middle English porche, from Anglo-French, from Latin porticus portico, from porta gate; akin to Latin portus port
1 : a covered area adjoining an entrance to a building and usually having a separate roof

Main Entry: terrace
Pronunciation: 'ter-&s, 'te-r&s
Function: noun
Etymology: Middle French, platform, terrace, from Old French, from Old Occitan terrassa, from terra earth, from Latin, earth, land; akin to Latin torrEre to parch
1 a : a colonnaded porch or promenade b : a flat roof or open platform c : a relatively level paved or planted area adjoining a building
2 a : a raised embankment with the top leveled b : one of usually a series of horizontal ridges made in a hillside to increase cultivatable land, conserve moisture, or minimize erosion
3 : a level ordinarily narrow plain usually with steep front bordering a river, lake, or sea; also : a similar undersea feature
4 a : a row of houses or apartments on raised ground or a sloping site b : a group of row houses c : a strip of park in the middle of a street often planted with trees or shrubs d : STREET
5 : a section of a British soccer stadium set aside for standing spectators