What are the differance between trail/motorcross bikes?

i want to get a dirt bike and i want to know which one to get im 13 and 135 pounds and im 5 foot 5 and i like to go fast and go on trails and goof off i need al little help finding a bike

aaahhhh ...they are alll rad get both

drink water

Also "trail" bikes have a headlight - useful when riding through dense forests, riding in overcast weather and night time.
"Trail" bikes usually come with electric start - useful after a long day of riding and you're to tired to kick start a stubborn engine, or get stuck on the side of a hill, trying to keep your balance.

Trail bikes tend to be lower power, lower speed gearing, and tuned for bottom end torque with precise vernier throttle power control, all obviously intended for wearing an 80 lb pack and picking your way through slashy areas, possibly also pulling a small trailer with a harvested deer on it. The original Elsinore typified the wave of outrageous lightning-fast motorcross bikes it created, in that the throttle response curve more resembled an on/off switch, and the stiff suspension was clearly intended for a lot of air time! Lots of bikes are some combination of both of these two archtypes, which define a continuum. Choose,Dude! Regards, Larry.

better suspension package on motocross

Trail is 4-stroke, motorcross is 2-stroke, 2-strokes are more racing and jumps, 4-stroke is more trails hills power bike, if you get a 2-stroke i would try a rm 85L, 4-stroke get a TT-R 125L

Well trail bikes would be what the industry refers to as their "off road" line. Only a very few of those are liquid cooled woods racing bikes like the CRF-X and WR-F lines. Most bikes in that category are low powered air cooled play bikes that are heavy and have very little suspension. If you really want a fast bike for your size to ride trails on the CRF150R would be your best bet. It is a motocross bike, but there are no high performance "trail" bikes in your size with the exception of the KTM85XC. Also most "trail bikes" no longer come with head lights so don't use that criteria to tell which is which. Jim is correct that the woods racing bikes have head lights, but bikes like the CRF-F line do not.

trail bikes can't race on a track.
Less power

Motocross are fast

The problem is that there are just so many things that effect what kind of bike you need. If you have no riding experience you should probably stay with the Honda CRF-F / Yamaha TT-R line of bikes, from 100cc-250cc. If you do have some experience riding I agree the CRF150R would make you a great bike. I would probably stay away from 2 strokes, there is slightly more maintenance that you must stay on top of. A huge factor of what kind of bike you'll be happy with is what your friends are riding. I agree you shouldn't concern yourself with them or what they have but it's true. If they're riding bigger faster bikes than a smaller slower bike won't make you happy.

Trial Bikes - moto cross bikes detuned for reliability and wider power band. Often trail bikes get lights.

Most are both 4 strokes today.

MX bikes have a closer gear ratio than street/trail bikes, more aggressive tires, and usually more suspension travel. MX bikes can have more top end power whereas a trail bike will have more mid-range torque. If you don't have much riding experience, I would get a trail bike. They are more ride-able but can still go!