Well, they may make sense to you Cc, but I've yet to find a clear & consistent definition of any of the above.
If you mean that we should have saws that we
personally find just right for doing each of those jobs, I fully agree! Backsaws come in a bewildering number of sizes, lengths & tooth pitches, rip, X-cut & "in between". 'Twas ever thus, & I propose that's because we each develop our own preferences in saws. As D-W said above, a certain guru was espousing whopping great saws for fine work a few years ago, which I found strange - what is the point of pushing around twice as much metal as you need for the job? Length matters for comfortable sawing, you want a saw that is long enough to give you a good full stroke, and that depends on your anatomy and preferred working height. Sawing with a very short saw gives a choppy, tiring style, and if the board width is more than half the length of the tooth line, some teeth won't exit the cut on each stroke to dump their load of sawdust. It's largely a matter of what you begin with & get used to, but I find a tall saw is harder to place intuitively on the plane of the cut, & it's not the one I'd reach for to cut any tenons in furniture-scale work. Here I'd use either a 10" or 12" saw with 2 1/2 & 3" depth of cut respectively. For dovetailing & small tenons, I prefer a 9" saw about 2" deep & 15tpi; it's light & maneuverable and the surface it leaves allows me to fit off-saw, as demanded by the old cabinetmaker who mentored me in my early days. I do own a hefty 14 x 4" which is handy for sawing very large tenons etc, & as pointed out by D-W, there is nothing wrong with using a handsaw for cutting large, deep tenons (actually, I prefer a panel saw if the job's too deep for my largest tenon saw). These are simply my preferences, your mileage will vary!
My advice is to find saws that suit your sawing style & the scale of work you generally undertake, keeping the above criteria in mind. This may take time & your preferences will almost certainly change as you gain more experience, but that happens with many (most?) other hand tools. Tooth pitches & patterns matter, of course, but it's a complex business & I could prattle on for pages about that aspect. To keep it simple - with pitches finer than about 15tpi, the difference between the quality or speed of cut from a crosscut or rip pattern is too minor to matter to the average person (it didn't matter to Tage Frid, who was a reasonably competent woodworker
). With larger tooth sizes & in some woods, tooth pattern can make a huge difference to cross-cutting, but if your work style is to whack off a piece with a comfortable margin & trim to the line on a shooting board, speed of cut is probably more important to you than quality, so any old saw will do if it's sharp. A poorly-filed crosscut can be both hard to control and make a more ragged cut than a sharp rip saw of equivalent pitch. If you need/want to cross-cut cleanly & close to a line, a suitably-pitched & well-sharpened crosscut can make all the difference.
It is much easier to learn to sharpen a ripsaw tolerably well, so these are where you should start. For a beginner it makes sense to have your crosscuts, at least, sharpened professionally at first. You can touch them up lightly between major sharpens & sets which extends the time between spending money & gets you started on saw sharpening. Most amateurs, just don't get enough practice to become really proficient, but most can learn to do an acceptable job & even a not-so-well-sharpened saw cuts far better than a dull one!
Cheers,
Ian
