In the Book of Mormon, the city of Jerusalem in Israel was termed a "great city" by Nephi (1 Nephi 1:4; 10:3). Nazareth, the place where Jesus Christ grew up, was called merely a "city" (1 Nephi 11:13). According to John Sorenson, the distinction is significant. The terminology applied by Nephi to Jewish Jerusalem and Nazareth gives us an idea about the size and function of the settlements called cities in Book of Mormon terminology.
Research on cities in the ancient Holy Land helps us grasp the meaning of Nephi's use of the term "city," and perhaps later usage of that word in the Book of Mormon. Six types of cities have been distinguished for the Iron Age II archaeological period, which extended down to Nephi's day.
1. The royal capital cities, Jerusalem and Samaria (compare Zarahemla, "the capital city," in Helaman 1:17), had a unique status. The former is estimated to have ranged from about 32 acres and 5000 inhabitants in Solomon's day to well over 25,000 on at least 125 acres in Lehi's day. Samaria may have encompassed 170 acres, with a 6.4 acre rectangular acropolis at its center as the formal royal seat. For a comparison in scale, note that Temple Square in Salt Lake City is ten acres in extent.
2. Also called "cities" in the Jewish record were major administrative centers, each over a district of the kingdom; these ranged from 12 to 17 acres in size with population a maximum of a couple of thousand; much of the space was occupied with administrative structures.
3. Secondary administrative centers constituted smaller "cities."
4. Fortified provincial towns were smaller still but boasted a defensive wall, which qualified them as "cities."
5. Fortress outposts were also called "cities," although they were so condensed that they typically included only dwellings for the commander and his staff, administrative buildings, storage space and a small temple (or shrine?).
In addition to these several types of settlements for which the term "city" is used in the Old Testament, there were of course smaller units such as villages.
Overall the meaning of the Hebrew word which has been translated as "city" probably centers on two functions--a site's having been established as a governmental center (including a temple or cult center as a symbol of royal patronage or presence), and its preparations to be defended militarily. Size had little to do with use of the label; many a "town" or even a "village" could have had more inhabitants than certain cities, but they lacked the crucial criteria to qualify for the name "city." [John L. Sorenson, "The Settlements of Book of Mormon Peoples," in Nephite Culture and Society, pp. 140-141] [See the commentary on 3 Nephi 9:3]