Joshua 21 describes the allotment of cities to the Levites, who did not receive a territory of their own like the other tribes of Israel. Instead, they were given specific cities scattered throughout the territories of the other tribes to live in and use for religious and administrative purposes.

Therefore, Joshua 21:14, "Jattir with its suburbs, Eshtemoa with its suburbs," means that the Levites were given the cities of Jattir and Eshtemoa, along with the land surrounding those cities (the "suburbs") for pasture and other uses.

Here's a breakdown:

Jattir and Eshtemoa: These were specific towns or cities. Jattir is often associated with the southern part of Judah. Eshtemoa was also located in the southern hill country of Judah.
With its suburbs: The Hebrew word translated as "suburbs" generally refers to the open land surrounding a city, often used for grazing livestock, gardens, or other agricultural purposes. This provided the Levites with land to support themselves and their families. These were not "suburbs" in the modern sense of residential areas, but rather more like agricultural land extending from the city walls.

Significance:

Levitical Provision: This passage highlights God's provision for the Levites. Since they weren't given a tribal inheritance, the other tribes shared their land and resources to support them.
Distribution of Religious Influence: By dispersing the Levites throughout the land, their influence on the spiritual and moral lives of the Israelites was expanded. They served as teachers of the Law and keepers of religious traditions.
Specific Allotment: The specific mention of "suburbs" emphasizes that the Levites were given not only cities to live in but also the necessary surrounding land to sustain their livelihood.

In essence, the verse describes a specific allocation of land to the Levites, providing them with places to live and resources to support themselves while they fulfilled their religious duties among the tribes of Israel.