Meaning and use of ideograms around "language" : 说，话，语
All Chinese character has its meaning or meanings. Some can be used as a word on its own, 

For example:

Noun: 


人(person(/ people/ human)
火(fire)   
山(hill/ mountain) 


Verb: 


殺(kill)
跑(run)
吃(eat)


Adjective: 


大(big)
小(small)
好(good) 


However, the majority of Chinese words are composed of two characters. 

For example: 


正確(correct) 
討論(discuss/ discussion)
明白(understand) 


*See reference here 

As for your question: 


說 is mostly a verb for "speak" or "talk" but it can combine with other characters to form more specific words. For example: 演說 (lecture/ public speech), 說服(convince/ persuade), 說明(explain)
話 is mostly a noun for "spoken words" but it can combine with other characters to form more specific words, for example: 謊話(lie), 說話(speak/ talk) , 對話(conversation)
語 is mostly a noun for "language" but it can combine with other characters to form more specific words, for example: 語言(language), 英語 (English), 語音(speech tone)


Many characters' original meaning had became obsolete. These characters only become meaningful when they are a part of a "two characters word" or a part of a "four characters phrase". One good example would be "黷" in "窮兵黷武" . The character: "黷" itself originally meant "act wantonly" but today, no one would use this character on its own except in the idiom 窮兵黷武.