After adding items to a project, you can then upload them to the pending queue on the server where they are reviewed and approved by an administrator before being added to a collection.
The location and method you choose for uploading depends on your security policies, your file storage arrangements, and your networking environment. The upload method for your project is specified in the Project Settings Manager.
You do not have to upload all project files to the pending queue at once. You can select any files from your project spreadsheet as they are ready. The Upload Manager in the Project Client can provide feedback about your upload, while you continue working in the Project Client.
Note: Although a project can contain more than 10,000 items (including compound objects), to maintain acceptable upload times, we recommend you upload items to your collection in batches of about 10,000 items per upload.