"Cart Tracks Well" What do people mean?

I'm fairly new to Turntables but have learned a lot. One thing I don't understand (and I see it said a lot in forums)... Is comments like "it's a great tracker!" When referring to or justifying carts. I realize there are track testing lps...but I can't imagine all these people are referring to their test results. I also realize bad tracking can affect sound quality... do folks think they can hear great tracking...or is it common for people to have arms jumping around when tracking is not good.

Honestly, I really want to know.

As OCD as I am, I've never had to wonder if my carts were "good trackers."
Assuming the record, stylus and cart are all in good condition to start (big assumption), if one hears noise or distortion that correlates with the location of the needle tracking the record and not the content of the music alone, that is often recognized as "bad tracking". You would hear the same noises and distortions at the same time each time you play the record, so its possible to determine that the needle is not accurately "tracking" the waveform embedded in the record.

Also note that records are prone to many imperfections. A "good tracking" cart/turntable will be able to play most or nearly all well without tracking related noise or distortion.

A turntables job is to play the record at the proper speed, not introduce any noise as a result of its operation, and track a record accurately (ie reproduce the waveform embedded in the grooves of the record accurately). When it does all three things well, then you are where you want to be for best possible sound. The cartridge is an important and integral part of that. REsults can vary widely in tracking ability from cart to to cart.

If teh cart is not tracking well, then there may not be much that can be done elsewhere to make things right, so getting teh cart to track well is perhaps the most critical thing in getting a good vinyl setup in place.

Another symptom of extreme "poor tracking" is if the cart jumps the groove completely especially during big dynamic passages. Some of the original Telarc digital lps from the late 70s/early 80s were renowned for being perhaps the toughest challenge out there for a turntable/cart to track. I did not rest back then until I was able to play those records well. Most common Japanese made tables with S shaped arms in the day could not with most any cart back then. I have not owned any like that since.
Mapman, Thank you so much for your thoughtful and thorough response!
IIRC, the 'cart tracks well" terminology came from the Telarc release of the 1812 overture.

Many carts of that day had major problems with the canon shots on that LP. If a cart could track those grooves at it's recommended VTF, then it was considered a great tracker and all other carts would be compared to it.

IMHO, it was way over rated for what it was.
I have a record that is warped as hell,
but on my deck it plays damn well.

On my Michel Gyro SE I have Shelter 501 basic with SoundSmith retip stage2.
Not only cartridge plays the role in tracking but tonearm as well.
It's also perfect balance set with anti-skate. Mine is set to half-gram while VTF is 1.8g. Proper VTF is also important.
Good point that a "good tracker" will track a warped record better and there will be less or no noise correlated to the location of the warp in the record. Warped records are usually the hardest to track at the beginning or outer grooves where warping tends to be greatest, especially if are unfortunate enough to have a turntable with platter diameter less than the record being played. I think I've found a softer cushioned surface on teh platter may provide better support and reduce the negative effects of a warped record somewhat.

Also worth noting that its the cartridge/tonearm combo that mostly determines how well a record is "tracked".

My current turntable is by far teh best tracker I have had. Its a mid 80's vintage Linn Axis with Linn Basik tonearm and Denon DL103R cart.

It never mistracks and is very quiet even with warped records.

I think I still have the Telarc 1812 lp with the cannon shots. I'll have to give that one a try...