They are one and the same. Few boards do not give 10th passing certificate. They only give marks sheet. So even if you upload marks sheet instead of passing certificate, you are good. Just follow this instructions while uploading images.

Uploading of Photograph: Instructions

Must be latest passport picture in a white background with the Name of the candidate and date written on the photograph. The Size must be 50 Kb to 300 Kb and format should be JPG.

The focus has to be on the face with 80% coverage and ears clearly visible.

Uploading of Post Card size photograph: Instructions:

Must be latest post card size picture in a white background with the Name of the candidate and date written on the photograph. The Size must be 10 Kb to 100 Kb and format should be JPG

Uploading of Signature: Instructions

Candidates must sign with a black pen on a white background in JPG format with a file size of 4 Kb to 30 Kb

Uploading of Left hand thumb impression: Instructions:

The file size should be 10kb-50kb in JPG/JPEG format.

Class 10th Passing certificate: Instructions:

File size of 100kb to 400 kb in JPG/JPEG format.

Hi dear

Yes, the Xth marksheet and the Xth passing certificate are different.

The Marksheet mainly consist of your subjects and their respective marks. Whereas, the passing certificate will mention only the subjects name,  declaring that you have passed Xth Board exam.

Although, there are few boards that doesn't provide passing certificate.

I hope, this answer was helpful to you.