Help understanding "line appearances" in phone cho

As I’m looking at different phones to use with an Asterisk system, I see options for 1 line, 2 lines, 4 lines, etc. Specifically, I’m trying to differentiate between the Linksys SPA921/SPA922/SPA941/SPA942. In the user guide (found at … tFHgeHnW5Q)
it shows the main difference being the number of “Voice Lines”, ethernet ports, and Power over Ethernet capability.

Doing a search here in the forums, it seems any combination of phones, lines, handset, etc all turn up tons of irrelevant results (for obvious reasons…) Anyway, can anyone explain to me what capability is added by these phones having different numbers of voice lines? (I sort of assumed I could give phones aliases in Asterisk in order to ring groups, all, individuals, etc.)

When you do out-going calls, the callee sees a different caller ID when you select a different “line”. When a call comes in, an indicator can tell you which “number” the caller dialed.

So if it were preferred to actually have all outgoing calls show up as the same number and incoming calls show the same number, the 1 line option is fine? I would still want the ability to put one call on hold and then call another extension, have conference calls, etc.

Sorry if these are dumb questions, but I’m trying to price out equipment for a proposal for our company to switch to Asterisk, and I don’t want to spend too much on phones if the only feature difference is something we don’t need/want.

The only feature I would hesitate about single “line” phone would be conference. In fact, Grandstream’s BT100 (bottom of line phone) has both hold and conference features. But if you must use phone based conference, multi-line phones may have better performance.

If you plan to implement conference in Asterisk, the conference feature in the phone has no meaning.