Different kinds of shelters or dwellings. In the OT the Hebrew word translated “inn” or “lodging place” might refer to a camping place for an individual (Jer 9:2), a family on a journey (Exod 4:24), an entire caravan (Gen 42:27; 43:21), or an army (Josh 4:3,8). In these passages (with the possible exception of the reference in Jeremiah) the presence of a building is not implied. Often the reference is only to a convenient piece of ground near a spring. It is doubtful that inns in the sense of public inns with a building existed in OT times.
By the time of Christ, the situation is quite different. Public inns existed in Greek times and throughout the Roman period. The Greek word for “inn” in the NT implies some type of stopping place for travelers. At times it refers to a public inn. Such an inn of the first century consisted primarily of a walled in area with a well. A larger inn might have small rooms surrounding the court. People and animals stayed together.
Inns generally had a bad reputation. Travelers were subjected to discomfort and at times robbery or even death. the primary services that could be depended upon were water for the family and animals and a place to spread a pallet.
In addition to referring to a public inn, the same Greek word for “inn” at times refers simply to a guest room in a private home (Mark 14:14; Luke 22:11).
In Bethlehem, Joseph and Mary could find no room at the Inn (Luke 2:7). This may have been a guestroom in a home or some kind of public inn. The reference in Luke 10:34 is clearly to a public place where the wounded could be fed and cared for by the innkeeper.