you are correct. back in the day, macs used a motorola chip, while the pc's used intel chips. about 10 years ago, apple started using intel chips, so they're essentially pc's. however, economically, the two are marketed towards very different users. macs are aimed towards those who favor simplicity and style, while the pc's have been aimed for value and power.
imho, they're different enough that i would still warrant the mac vs pc discussion.