In UNIX computing, the system load is much more than just another Number. Ok Great so what does that mean? Well I am glad you asked. The load number generally is under the format of x.xx (such as 0.23) and it simply expresses how many processes are waiting in the queue to access the processors.
The smaller the number the better the load - and the higher the number - generally is associated with a decrease in server performance. While server load is just one of the factors out of many othes (such as cpu usage, swap file size, ram/memory usage etc) generally the load is influenced by each of the aforementioned.
For example - if you run top and see that your swap file is being used heavily - chances are you may not have enough ram - since the swap file is on the hard drive - suddenly the disk now needs to spin not only to handle grabbing and writing data for its processes but also to act as RAM.... this causes the I/O to get higher and therefore the load to rise...
While this is a simple fix - just add more internal memory - other issues may not be.
Generally we suggest starting with the TOP command and looking at the amount of ram / swap in use.