solder vs soft solder

solder and soft solder both are nouns.

Word	Noun	Adjective	Verb	Adverb
solder	Yes	No	Yes	No
soft solder	Yes	No	No	No

As nouns, soft solder is a hyponym of solder; that is, soft solder is a word with a more specific, narrower meaning than solder:

solder: an alloy (usually of lead and tin) used when melted to join two metal surfaces
soft solder: solder that melts at a relatively low temperature

Other hyponyms of solder include hard solder, silver solder.

solder (noun)	soft solder (noun)
an alloy (usually of lead and tin) used when melted to join two metal surfaces	solder that melts at a relatively low temperature

solder (verb)	soft solder (verb)
join or fuse with solder