The media library contains all the images and documents you’ve uploaded to your site. The media library allows you to name and caption files, view the files and delete the files.

You don’t have too use the media library in advance of inserting images in your pages and posts. It is possible to simply upload an image or PDF into the page or post that you’re working on in that moment.

Supported file types include JPEG, Gif, PDF, .doc, .xls, mp3, mpeg… in fact any file supported by IIS or Apache web servers.

These files are added to an “uploads” folder. In the Settings > Miscellaneous you have more control over how WordPress stores your media files.

Tip: Note that you can not use an FTP client to upload files as the database will have no awareness and therefore no connection to files added in this way. The are however plugins that offer similar features to FTP features.

JPEGs & GIFs

Typically an image would be a JPEG file or a GIF file. You have to be careful not to upload very large JPEG files (more). Ideally your JPEG’s should be about 600 pixels across and about 400 pixels deep. GIF files are generally smaller anyway because the GIF file format restricts the number of colours that can be used.you may need to find a program on your computer that is capable of resizing JPEG images down to 72 dpi and 600 pixels across.

PDFs

It is also possible to create and upload very large PDF files. So when you are outputting your PDFs it’s important that you look for a “web option”. You should try to avoid uploading PDF documents of over 5 MB. This is because if you upload a number of 5 or 6 MB sized PDFs you will start to find your website uses a lot of bandwidth as many people come by and download the PDF.