CST Tax is Central Sales Tax there are 2 types of taxes when some one sells the good 1. is VAT (Local sales Tax)
1 VAT (Local Tax) When someone in Maharashtra sales goods whtin maharashtra it is calles as local sale and there is tax imposed at all levels of sale that means when sell something with in same states u have to pay local tax i.e. VAT, the tax collected from these sales will be used by state government

2 CST when some one sells goods from one state (eg maharastra) to other state (eg. in gujarat) it is called as inter state sale and this time central government comes in picture any kind of sale whrere goods trravels from one state to another central sales tax is imposed and tax collected from such sale is used by central government