MPU6050 registers VS FIFO?

I have an MPU6050 connected to a slave accel via the auxiliary I2C.
Now, if I have to read the accel and gyro data with DMP enabled, we normally read the FIFO.

At this point of time, ACCEL_X(Y,Z)OUT_H(L) registers also contain accel data.
Similarly gyro data contained in GYRO_X(Y,Z)OUT_H(L) registers.

What is the difference between the data stored in FIFO and these registers?

Is it that data read from the slave accel first stored in the ACCEL_X_OUT_H registers, then processed/used by DMP and finally stored in FIFO?