What does "user storage is full" mean in the Discussions area?

Community Novice

My students are using Discussions to upload their work so we can critique it. Several of my students are unable to upload their work to Canvas (though we’ve been doing this throughout the remote learning period) because it’s telling them their "user storage is full". I have just deleted a number of earlier discussion boards in hopes of making room for their work. Is this the problem? Thank you for your help with this.