EDIT: Thanks for the explanations, guys!
EDIT: Thanks for the explanations, guys!
A LUT is, more or less, the smallest logical element on an FPGA (a piece of programmable hardware) -- it's a Look-Up Table. They're not directly comparable from FPGA to FPGA, because some FPGAs have different sizes; in the early days, LUTs had 3 inputs and produced one output, but on modern FPGAs, 'LUT4's (4 input, 1 output) are the smallest that you'll reasonably get, and some FPGAs even use 'LUT6's (6 input, 1 output; sometimes divisible into 5 input, 2 output, or other subdivisions) as their basic logic element. But no matter how you slice it, 308 LUTs is impressively small, especially for 180MHz.
LUT = Look-Up Table
LUTs are the building blocks of FPGAs.
A chip half-way between a PAL (think of a dozen or so gates in a small package, you could choose how they were hooked up; it was fast and it was small) and an FPGA (relatively huge and expensive). Both programmable, but PALs usually only once.