Bokeh — a wonderful word whose origin is (I believe) Japanese but might be Korean — means the softening of backgrounds in portraits and macro photography. Some lenses are designed to do it, others are intended to “go deep and sharp.” You have to pick lenses based on what you intend to do.
My two best lenses for bokeh are my portrait and macro lenses. A few others do a credible job, but those two are better. Also, in my admittedly limited experience, zoom lenses don’t give you the kind of bokeh you can get from a prime. Then again, I’m a big fan of prime lenses and would use them all the time if I didn’t hate carrying a lot of equipment. Also, I’m phobic about changing lenses outside in weather. Who knows what the wind may do to the innards of my camera? Will I find a table so I can make the swap comfortably?
When I’m shooting outside, I use a 12-200 mm (translates more or less to a DSLR 24-400 mm) Olympus lens as my all day lens. It gets close, yet also goes wide. It’s very convenient. It’s not as sharp as most of my primes. It’s also a bit noisy, and it’s an f4, which is okay outside in daylight, but too slow otherwise.
My very long 100-300 mm birding lens has excellent bokeh, especially when fully extended. I don’t know enough about optics to explain exactly how lenses work, but I’m good at following instructions.