Buffers whose names start with a space are invisible to many operations. These are generally internal buffers that you don’t want to see. Their names normally don’t appear in the buffer list or as Completion candidates when you switch buffers using ‘C-x b’.

You can see an invisible buffer if you want to: just type the leading space in the name. Since most commands that read buffer names perform input completion, and the ‘SPC’ key (space bar) sometimes has a special meaning during completion, you might need to use ‘C-q SPC’ to insert a leading space character. For example, to switch to a buffer named ` *Deletions*’, you would type `C-x b C-q SPC *Deletions* RET’.