Sometimes, when I read descriptions of books, I think "Okay, that's nice. But that's just a situation--where's the plot?"
Pro tip: You want your novel to have a plot. Actually, your novel needs to have a plot.
But sometimes, writers don't have a plot. They think they do, but what they actually have is a situation.
Here's an example. Try these two book premises:
Sarah is just trying to survive her senior year of high school. She's just broken up with her longtime boyfriend, and her best friend is drifting away from her. On top of all this, she may be about to lose the job, which was her only source of money to pay for college.
In order to survive her senior year of high school, Sarah must deal with the pain of losing her longtime boyfriend, while struggling to repair her relationship with her best friend. At the same time, she must also find a way to keep the job she's desperate for.
The difference is subtle, but it's there. The first snippet is an example of a situation, and the second if an actual plot. So what's the difference?
The first example simply lists a bunch of circumstances. It's a description of the current state of Sarah's life. While things may be happening, there's no hint of conflict. Saying that she broke up with her boyfriend or that she's about to lose her job is not saying that there is a plot. It's not conflict at all; it's just a situation that Sarah is in the middle of.
The second example, then, has some elements of an actual plot. There are concrete goals, both internal and external. There are things Sarah must do. She must fix her relationship with her best friend, overcome personal issues, and hold on to her job. These things all are various forms of conflict. There's conflict with Sarah, conflict with her best friend, and conflict with her employer. This is the beginnings of an actual plot.
In their simplest form, plots are about conflict. They are about people doing things. They are more than a set of circumstances or the current state of someone's life, which, in terms of fiction, is mainly static. Plots are about movement. They flow and they progress and they build on themselves. You want your story to have this movement. Otherwise, it won't have a plot at all and we'll all be bored.
The trick is to learn the difference between a plot and a situation. Situations, of course, have their place, and are great jumping-off points. However, you can't write a whole book off them. To have a novel with actual conflict, you'll need a plot.