It takes four 4-bit groups (four elements, four bits per element) and inverts each input to its corresponding output, with a common output-enable (OE) per group that puts the outputs into high-impedance when asserted. This makes it the go-to part for bus isolation and signal inversion on a 3.3 V backplane or memory-address bus where you need to disconnect a section without loading the line.
12 mA output drive — what it can and cannot do
The symmetrical 12 mA source and sink capability is typical for a 3.3 V bus buffer. It will cleanly drive a few CMOS loads on a short PCB trace (say, up to four or five standard 74LVC inputs), but it is not meant for driving a 50 Ω backplane or a long cable — for that you would step up to a 24 mA or 32 mA driver like the SN74LVTH16245.
Package and footprint — 48-BSSOP
It is a surface-mount fine-pitch package (0.635 mm pitch typical for SSOP) that requires a standard SSOP-48 footprint. The tube shipping medium means it arrives in anti-static tubes, not tape-and-reel — plan your pick-and-place feeder setup accordingly if you are using it in volume.