Reference clock is just that...an external clock used as a reference, what speed is the oscillator on your board?
axi_stream_clock is the clock speed of the data stream within the FPGA fabric itself.
sysref_in - not checked the product guide, so not sure, but try clicking on the + to expand and see what is there, it might give you a clue.
s_axi_clk - slave AXI clock, this is the clock at which the blocks within your FPGA fabric will operate at to communicate to one another and send basic information back and forth (like commands to adjust operational modes from the CPU), this in particular is a slave input and would connect to a master of some other device (CPU for example).
m0_axis_aclk - Master AXI Stream Clock, this is the clock speed of your actual data stream within your FPGA fabric, like for example with HD video this might be 148.5MHz, but your AXI clk for comms between modules might be something different
clk_adc0 - This looks like the clk speed of your ADC?? Not checked the manual, but I would say a pretty safe guess
irq - Interrupt Request