Ubuntu,backing up photos

[fred the great]

One would think backing up photos to a CD or DVD should be easy but for the life of me I can't get it to work? Methinks the brain is either addled or over worked.
I have tried dragging the photos over but they jump back with a note "permission denied" or something similar. I've done it  previously successfully, and now looked through the help pages and checked the Ubuntu Forum without any success.
So could someone kindly take me through the process as I am missing (I think) a vital step or I may have have changed some essential parameter without realizing it?
I can back up my other data to a thumb drive easily, and it's only the back up to a disk where something is amiss.

[pdm]

You need to use a disk burning program.... Under KDE this is "K3B", under gnome I think it is "Brasero" or similar.
Open the program, select the files to add to the image to burn - the programs usually give some indicator of the total size of files added in relation to the blank CD or DVD inserted and finally hit "burn" for the ISO image to be created and burnt onto the CD/DVD.
(Under K3B, you select "New Data Project" and then simply drag the files from the top pane to the bottom one and hit the "burn" button when satisfied. Brasero works in a similar "create" and "drag&drop" manner.)
"Automatic" burning by drag and drop onto a DVD or CD desktop icon is not, I believe, currently supported by gnome or KDE.

[fred the great]

Many thanks pdm. As soon as  I read your Post my brain started working again and I have already burnt about 20 photos with Brasero and written them to a DVD.

And of course checked the DVD.

Thanks again. Please have a virtual pint on me