Operations enable reversible modification of data -- they act like filters which process the data. The graph you see above represents the data after these operations have been run. Delete them to undo their effects, or to apply them in a new order.
#000-style suffix, like subtract:3243#2414 are referring to a specific snapshot (in this example, #2414) of another spectrum. Click to learn more.
These spectra are being temporarily displayed for comparison; Clear all