As a result, SOIC package contains the embedded device. 16 is the number of terminations on the chip. There are 8 bits on the IC chip. There is a subcategory of it called Shift Registers. It should only be used at temperatures below 70°C.
SN74LS599D Features
SN74LS599D Applications
There are a lot of Texas Instruments SN74LS599D Shift Registers applications.