A bottleneck refers to a point in a process where the flow or speed is restricted, resulting in a slowdown or delay. In the context of uploading files, a bottleneck can occur when either the upload speed is slow or the video file size is excessively large.

If the upload speed is slow, it means that the rate at which data is transferred from the device to the internet is limited, causing the upload process to take a long time. On the other hand, if the video file size is too large, even a fast upload speed may not be sufficient to expedite the process.

Identifying and resolving the bottleneck is crucial to ensure efficient and timely file uploads.