The patterns in the land help to identify urban, residential, and agricultural areas. Urban and residential areas have an obvious road system and agricultural lands have obvious patterns of fields. Rail transportation systmes seem to run in a straighter pattern than automotive systems. They also seem to go over whatever is in their way while automotive transportation systems are not as likely to go through natural obsticals. Yes, different kinds of vegetational covers can be identified.
Agricultural land is much more organized than nonurbanized, non- farming land.
Band 4 is the easist to use to see vegetation. Band 4 has the highest reflectance. Band 3 has the lowest reflectance. Spectral reflectance is the amount of light reflected from the land. For me, the features are easier to see using one band.