text messages与text messaging的区別

例句1: Chart B shows the cosplayt of sending text messages from these countries.

例句2: If you look at the cosplayt of text messaging, you can see that Company A is the cheapest from Spain and the USA.

请问为什么第一句用 text messages，第二句却是 text messaging? 两者用上有什么不同?

Thanks in advance.

text messages text messaging 有什么区别是：前者为可数名词的复数形式（其意较为具体），后者为动名词转化来的不可数名词（其意义相比较而言较为抽象）。其不同像 clothes 与 clothing。