Load averages tell how many processes are there waiting for their turn. The values are for one minute, five minute and fifteen minute averages.
So if the values are
and you have one processor, during last minute there has been 0.2 processes running, i.e 80% of the time the processor has being idle. During the last five minute there has being 1.2 processes running, but since there is only one processor, the 20% of them were waiting for their turn. During the last fifteen minutes there has being 12.4 processes running, i.e for each running process there have being 11.4 waiting. If you have several processors or multi-core processor, load under 1 is common.
If you run command
top, you see what the running programs (i.e. processes) are and how much they use processor, time and memory.