小説 and 物語: the novel form and a story
Distinguish a literary genre from a story that can appear in several media.
A fictional prose work
小説 (しょうせつ) means a novel or fictional prose work. 「短い小説を読みました」 means reading a short work of fiction.
「小説を書き始めました」 says the speaker began writing fiction. It does not establish completion or publication.
The broader story concept
物語 (ものがたり) means story. 「祖父から昔の物語を聞きました」 means hearing an old story from one's grandfather.
「物語の続きが気になります」 expresses interest in what happens next. It does not establish knowledge of the ending.
Genre and content
Fictional prose can contain a story, but not every 物語 belongs to the 小説 genre. Spoken or screen-based stories can also be called 物語.
「この小説をもとに映画を作りました」 says a film was made based on this novel. It does not guarantee that every scene matches the text.
Must a 物語 be a printed novel?
Show the answer and why
No. It can also be a story conveyed through speech or images.