Doesn't downsize mean to delete?
Yes, in some cases, downsize does mean to get rid of but in this case, downsize does not mean the same thing. When someone talks about downsizing a PDF, they are referring to cutting down the size of the file. It basically means compressing the files in a way that the content remains the same. Downsizing in this case means to make things more compact and efficient because having a bulky and large PDF file could be very problematic.
What kind of problems?
When you have PDF files that are bulky, it can be really inconvenient. Not only will it require more memory on your computer to store them, it also takes a much longer time to send and receive these files. When you choose to downsize a file, the results could be up to 1/100th of the original meaning the transmission time will go down substantially. Also, with smaller file sizes, you will never have a problems with exceeding attachment sizes.
How to start downsizing (PDFs)
If you want to start downsizing PDFs, you need to get your hands on a file compression software. CVISION is a leading provider in file compression software so their products are completely dependable. In my experience, it was the best one to use. You can even download a free trial of their PdfCompressor just to see if it is what you need. You can click on the link above to do that or if you still have more questions, you can contact CVISION directly.