使用.pch文件包含applcation文件

I just came to know that if we include anything in .pch file, we don't have to include later in other files. Now I am thinking of adding all of my files in it so that I don't have to include them in other files and create a mess at the start of each file. But I was thinking if this is a good practice? If not, why? And if good, why?I just came to know that if we include anything