In UNIX computing, the system load is a measure of the amount of computational work that a computer system performs. The load average represents the average system load over a period of time. It conventionally appears in the form of three numbers which represent the system load during the last one-, five-, and fifteen-minute periods.
We display the average as one number on the Server -> System Information page. Generally this number should remain relatively low (< 5.00). You should also know that the Server Information page only updates once every 15 minutes from the top of the hour so all your going to see is a snapshot of the system load at the last 15 minute interval.
You can also see the load the last one, five and fifteen minute periods by going to Server -> System Information -> Advanced Server Information -> Uptime section. Example is below:
load average: 0.13, 0.30, 0.38