What is the difference between the main root and the lateral ones?

All roots of one plant form a root system. In the root system, there are main, adventitious and lateral roots. Additional or additional ones that extend from the aboveground or underground part of the shoot. And the main one always develops from the root of the seed embryo, so it appears in the plant first (hence the name, even if later the main roots are lost among a large number of adventitious ones). Lateral roots are those that extend from the main one.