[landline phone] [fixed phone]

[sunsunmoon]

Is this a landline phone or a fixed phone?

[BobK]

Either. Possibly, a few people might make a distinction between a fixed phone (as in your pic) and a cordless phone that isn't attached to the wall but uses a permanent landline rather than a cellular network. But although that distinction is possible I haven't heard it being consistently applied. I might say to someone 'Will you call me on my landline' - and whether the receiver is tethered to the wall is none of their business!

b