text vs instalment

text and instalment both are nouns.

Word	Noun	Adjective	Verb	Adverb
text	Yes	No	Yes	No
instalment	Yes	No	No	No

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

text (noun)	instalment (noun)
the words of something written	the act of installing something (as equipment)
the main body of a written work (as distinct from illustrations or footnotes etc.)	a part of a broadcast serial
a book prepared for use in schools or colleges	a part of a published serial
a passage from the Bible that is used as the subject of a sermon

text (verb)	instalment (verb)
to send a message by SMS or similar text-based messaging service