Originally only one movie but eventually became a trilogy.  I my opinion they should have stopped after

Making the first movie.

The plot revolves around a Mr Anderson (A.K.A. Neo) and you follow him as he learns about the Matrix.  You really need to look at a two part episode on the Animatrix DVD that explains how man Produces a race of artificial intelligence based robots.  These creatures are used initially to do all the heavy work for the humans but for some reason they turn on them and the robots become outcasts.  The robots move to an island called something like A1; I can’t remember.  They become really successful in business and eventually become a threat to the status quo; who decide to invade the country and that is the beginning of the end for humans.  After many years of fighting, the humans decide to remove the only source of power that the robots could use and that’s the sun.  Beginning the resourceful robots; they realise that all was not lost and learn of the fact that humans could be a perfect source of power; just like a battery.

So they start to round up as many humans as possible to link them into a massive network.  They would be used to power everything they needed and even went as far as to farm the humans, just as a farmers might grow corn.  That’s right; humans would no longer be born in the traditional way.

The problem they encountered was the body would die if it didn’t have an active brain.  This lead to the building of a virtual world, where all the humans would believe that they were living a normal life.  According to Mr Smith;  the first batch of humans were lost, due to the fact that they didn’t believe in the perfect world that the robots had created.  So the decided on a world based on the late nineties (more likely due to the fact that that’s when the movies was made)

So we now get to the beginning of the movie that has Neo sleeping in front of a computer monitor and I must point out that he doesn’t know that he is in the matrix.  We follow him as he learns about the matrix of computers and how he can move beyond what would be considered normal.  He meets up with Trinity and eventually meets Morphius and he tells him that he is the one.  The one what?  Well I’ll leave it there and let you find out for yourself.