[Ask] Movement script: explanation

programming flash
1

I’m newbie in Flash and action script,just start learning T__T…

onClipEvent (load) {
speed=10;
}
onClipEvent (enterFrame) {
if (key.isDown(key.RIGHT)) {
_x+=speed;
} else if (key.isDown(key.LEFT)) {
_x-=speed;
}
if (key.isDown(key.UP)) {
_y-=speed;
} else if (key.isDown(key.DOWN)) {
_y+=speed;
}
}

anyone can explain the script above to me?is that making the object moving to left and right???
THANKS a LOT!!!