ecause I do not understand what the acronyms mean even with the legend.
Try to understand what each pin on the chip does.
I could be wrong because I haven't carefully studied the data sheet... The Address lines A0 & A1 determine which of the 4 DAC outputs you are addressing. (But you are not directly controlling the analog output, you are writing to an internal register). The LDAC line loads the data from the 12 parallel inputs into the addressed register (to be converted to an analog voltage). It looks like the R/W line determines if you are reading data into the DAC registers or writing the register data out to an analog output (at any moment in time.)
The most important thing about the timing diagrams is the sequence.