The key highway=* is the main key used for identifying any kind of road, street or path. The value of the key helps indicate the importance of the highway within the road network as a whole. See the table below for an ordered list from most important (motorway) to least important (service).

“Highway tagging samples”

Roads: motorway, trunk, primary, secondary, tertiary, unclassified, residential, service

Link Roads: motorway_link, trunk_link, primary_link, secondary_link, motorway_junction

Special: living street, pedestrian, bicycle road, track, bus guideway, raceway, road, construction, escape

Paths: footway, cycleway, path, bridleway, steps, escalator

Sidewalks : sidewalk, cycleway lane, cycleway tracks, bus and cyclists, lanes:psv, busway

Lanes: number of lanes, direction instructions (“turn lanes”), signposts

Data Source: highway=* osm.wiki/WikiProject_Bangladesh#To_Know_more_about_Bangladesh