system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: What are the key difference between Street, Avenue, Boulevard, Circle, Crescent, Place etc.?
gpt
In terms of their use in the naming of streets in modern towns and cities, they are basically arbitrary.  Some cities, especially with grid plan layouts, have certain conventions, like streets running north-south and avenues east-west, but there is no firm rule.

Historically, the names come from different sources, which once had distinct meanings.

Street comes from the latin, "via strata", meaning paved road.  Originally street indicated a paved road, and as those were almost always only present in towns or other built up areas, it came to indicate a roadway within a town.  The exception is roads that were actual Roman roads, like Wattling Street, that kept the name from Roman times.

A road is a route between settlements.  For example if you leave Cambridge and travel in the direction of Milton, a village near by, the route you follow is Milton Road, because that is the road to get to Milton.

An avenue was, traditionally, a route that is lined by trees on either side.  Often in a large wealthy person's estate, they would plant trees to mark an avenue from the great house to the gate or some other important place (eg from the house to the village church).

A lane is a minor route in the countryside, often in farming areas, mainly for access from the village to farming areas.

A court was originally a courtyard, that is an open area surrounded on all sides by buildings.  During the industrial revolution, in rapidly growing industrial towns, it was common for low cost slum housing to be built in the courtyards at the back of what had formerly been larger and more prestigious buildings, with the address of the housing being named for the courtyard they were built around.

A terrace, in English towns, is a set of houses built as a single unit, so a long line of houses together where each pair of houses shares a common wall, so when such a set of housing was built, the street it was on might be called a terrace to indicate this.  Houses built in this way is still referred to as "terrace houses" as distinct from detached, meaning the house is free standing, unconnected to its neighbours.

A Place is an open area in a town, for example a market square.

Boulevard comes from French, meaning a fortification.  In a lot of European cities, in the past there were city walls to protect the settlement.  In the industrial revolution era when cities grew rapidly, the walls became more of a hindrance, and in many places they were taken down and the route of the wall became a roadway.  The name boulevard in France indicated it was the route of the former fortifications.

In all of these cases, this is how the name originated, and it is common for the names in very old settlements to follow this pattern.  In any newer settlement, particularly in places settled more recently such as the US, the names don't have any specific meaning, they are just chosen because they sound nice.