If the ball is on the bottom, it's a "roller ball." If it's on the top and meant to be touched, it's a "trackball."
the ball....
A trackball, I believe.
A ball mouse
mechanical
Well the mouse sends the movements of it to the computer. A mouse with a mouse-ball has rollers inside of it that move with the ball and from there can operate similar to a keyboard. An optical or 'laser' mouse is much more advanced.
That's called a trackball. The device stays in place and you move the ball (usually) with your thumb, rather than moving a mouse which in turn moves the ball inside (or with the newer optical mouse, electronically senses the mouse motion).
The ball inside older mice - was either solid rubber - or a steel ball with a rubber coating.
The ball inside older mice - was made of a solid steel ball coated in a thick layer of rubber.
The laser or ball on the bottom.
A "ball mouse" or mechanical mouse is a computer mouse which detects user inputs using a system of servos detecting the movements of a ball (inside the mouse) which rolls on the desk surface. The most common alternative, the "optical mouse" uses optical sensors to detect user inputs. The optical mouse is widely considered to be superior in all important respects, and is therefore becoming much more common then their mechanical cousins.
if the mouse has a tracking ball under it, flip it over and turn the plate that holds the ball to the right(clockwise), remove the ball and using a pencil eraser or a toothpick remove the gunk on the tracking wheels inside of the mouse, make sure to shake or blow out all of the debris and put together. if that doesn't work buy a new mouse
A Ball Bearing
A tracker ball is both a the ball on top of a stationary mouse and a type of a mouse that has a ball on top. A typical mouse is moved over a pad and has the ball directing the cursor on the bottom, but a tracker ball type mouse has the ball on top of a stationary mouse where you direct the cursor by moving the ball with your thumb, FOREFINGER AND MAINLY WITH YOUR PALM. This type of mouse is sometimes called a tracker ball for short and the ball on this type of stationary mouse is also called a tracker ball. [ delete the following:...It is not a good name. What does it track? Nothing that I can tell. Computer terms were assigned by people who wanted to make it confusing, didn't speak English, or were very confused themselves] It would be better explained as follows. '''A tracker ball is both a the ball on top of a stationary mouse and''' [?a type of a mouse that has a ball on top]. '''A typical mouse is moved over a pad and has the ball directing the cursor on the bottom, but a tracker ball type mouse has the ball on top of a stationary mouse where you direct the cursor by moving the ball with your thumb,''' '''forefinger but mostly with the inner aspect of your palm. This type of mouse is used by people with arthritis or RSI as it saves making the fiddly and speedy movements with the digit joints (which cause some people pain) and directs the cursor by making a round movement after putting your hand over the large glass "tracker" which is on top of the "mouse". I myself was able to work as a secretary doing 100wpm until the age of 59 despite arthritic fingers since my late-40s, because an ERGONOMIC TRACKER MOUSE was recommended and purchased for me by my employers. I can highly recommend the TRACKER MOUSE to anybody - especially to those with arthritic hands and intermittent RSI.''' '''"Tracker Lover"'''
it is a ball or sometime a laser thingy
Optical
They both do the same job. And on an older mouse it's easy to see the similarities. An older computer mouse would have a ball underneath. Then as you moved the mouse around the ball would roll and the computer would count the rotations. A track ball was basically a mouse turned upside down. Instead of moving the mouse to rotate the ball, you'd move the ball directly with your fingers instead.