- upload_max_filesize - This is the maximum size of a file that can be uploaded
- post_max_size - This is the maximum size of data that can be received from the upload form (same or larger than upload_max_filesize)
- memory_limit - This affects the download procedure and should be set higher for large file downloads
Additional information can be found be searching the web for "PHP Upload File Size Limits", or by visiting the following url: http://www.cyberciti.biz/faq/linux-unix-apache-increase-php-upload-limit/