I can only say that DDR3 or the older generation (DDR, DDR2) are used for the CPU. Next generation DDR4 should be out in December of this year or during the winter.
GDDR5 is based on DDR3, but is designed for use in applications, such as the PS4. Accordingly GDDR5, is the same as DDR3 but faster, especially for consoles PS4.
Here's an article
on Wikipedia about GDDR5. Therefore, I can confidently say that it is the CPU.
The PS4 CPU is used: 8Gb GDDR5 (256-bit GDDR5 (effective frequency of 5.5 GHz) with a bandwidth of 176 GB/s)
Unfortunately I can't say characteristics, with regards to video memory.