Very good question, indeed, I can attest to this as I was a Presbyterian for years.
My Mothers people are Irish and Scottish born.IN Scotland one is Presbyterian .. of one branch of three. { basically }
The Orthodox Presbyterians, are very rooted historically in Scottish Covenanter tradition. There are no instruments in Church, and only Pslams and Hymns are sung.
Then there is the Reformed Presbyterian which is not as strict as the one mentioned above.
After these two follow the Presbyterian Free Church which is very evangelical and more lenient than the two before it mentioned.
These three teach Salvation by faith through noone else but JESUS CHRIST.
Then there is the Presbyterian churches here in the USA that are so liberal they have gone mad.My own onceupon a time Presbyterian Church USA has denied the very " deity " of JESUS CHRIST.Also they have denied the in-errancy of scripture and its authority.They have fallen apostate.
Much of this has been an absolute shock to my families born and raised in Scotland, living there yet still today.
The PCA is more conservative than the larger PCUSA on matters of Biblical and doctrinal interpretation and social and political stands. Like the PCUSA, the PCA accommodates different views of creation and strives for racial reconciliation which in and of itself is a good thing but its focus has gone awry.
The PCA is generally less conservative than the Orthodox Presbyterian Church (OPC) and more conservative than the Evangelical Presbyterian Church, though the differences can vary from presbytery to presbytery and even congregation to congregation.
For example, some churches in the PCA allow women to do anything a non-ordained man can do, such as teaching co-educational Sunday school classes, whereas other churches in the denomination only allow women to teach women and children.
It all has quite a history and can become somewhat confusing. I

Yes.