Are you guys sure you're not confusing product lines? PPC is a PowerISA architecture, but hasn't been pushing desktop/server level performance for, what, almost 20 years? It's an embedded chip now, and AFAIK IBM doesn't even make them any more. Power (currently "10th gen"(-ish)) is the performant aarchitecture, used in the computers formally known as i-Series, formerly known as RS/6000. It's pretty fast, not not price competitive. They aren't really the same thing.

"PowerPC" was a modification of the original IBM POWER ISA, which was made in cooperation by IBM, Motorola and Apple.

Motorola made CPUs with this ISA. Apple used CPUs with this ISA, some made by IBM and some made by Motorola.

While Motorola and Apple used the name "PowerPC", IBM continued to use the original name "POWER" for its server and workstation CPUs. Later IBM sold its division that made CPUs for embedded applications and for PCs, retaining only the server/workstation CPUs.

However, nowadays, even if the official IBM name is "POWER", calling it "PowerPC" is not a serious mistake, because all the "PowerPC" ISA changes have been incorporated many years ago into the POWER ISA.

So the current POWER ISA is an evolution of the PowerPC ISA, which was an evolution of the original 1990 POWER ISA.

It is better to call it POWER, as saying "PowerPC" may imply a reference to an older version of the ISA, instead of referring to the current version, but the 2 names are the same thing. PowerPC was an attempt of rebranding, but then they returned to the original name.