A trail is a route, usually quite long, and nowadays marked on maps and signposts on the ground, though historically this may not have been so. A path or footpath is usually shorter than a trail ; it may be paved or not, and it may or may not be near or alongside a road. In England the path that runs alongside a road is usually called the pavement, and a path or footpath goes somewhere away from a road. Behind my apartment block there is a footpath that links two roads and which enables people to take a 'short cut' - a quick route - to get from one road to the other. A path may also be used by bicycles, and in the countryside there are bridle paths or bridleways for people riding horses.

‘Footpath’ is a term used in British English. Americans have sidewalks. We do use ‘bike path’ however. ‘Paths’ by themselves are informal. They designate a way through an obstacle. ‘Trail’ is the common term for something substantial with a name but they might be open to bicycles and horses (designated ‘multi-user’) A trail open only to walking could be designated by ‘hiking’, or ‘pedestrian’ depending how wild the surroundings are.

"Path" is a very general word with many different shades of meaning. The core meaning is the same as "way" or "route." It can be used figuratively: "the two different theories take different paths to arrive at the same place." In the context of walking, it suggests something intentionally built, and in good condition. It is not for cars, but not necessarily restricted to pedestrians. There are "bicycle paths." "Footpath," of course, means a trail specifically for pedestrians. It suggests a narrow path. "Trail" brings to mind a path through the woods. It suggests something rough and unpaved. It is a possible route you can follow, through terrain that is difficult to walk through. A trail might be created simply by many people walking in the same place--a "beaten path." A "trail bike" has thick tires that can ride over dirt, rocks, and tree routes. It may be hard to see a trail under your feet. You may follow it by markings on trees, "blazes." To "blaze a trail" is to discover the best path and mark it so that others can follow it.

"Footpath," "path," and "trail" generally refer to pedestrian routes, but there are subtle differences. A "footpath" is a narrow path for pedestrians. "Path" is a broader term encompassing any walkable route. "Trail" often implies a marked path, typically through nature, suitable for hiking or walking. The distinctions can vary regionally and contextually.

In the UK we have what are know as 'public footpaths'. These are recognised paths the public can use to navigate the countryside without wandering onto private property. A good regional map will often have public footpaths marked on it. (There are also 'bridle paths' which are suitable for those riding horses)