Gable Style Trusses like these are often referred to as ‘commons.’ Webs (and joints) are arranged in such a way that they create triangular spaces inside the truss, and that lumbar and plates in the truss are optimized.
In general, the maximum distance between top chord joints on roof trusses is about 8 feet, and 10 feet on bottom chord joints. Therefore, the longer a truss is, the more joints and webs it needs.