The plot is rather difficult to interpret simply.
But rather vaguely, it shows of frequency of hot and cold spots of various angular sizes (as indicated by the upper axis) on the sky (FK-652--653). Large spots are on the left; small spots on the right.
The data points come from the experiments WMAP, ACBAR, BOOMERanG, CBI, and VSA.
The curve is fit to the data???---but with how many free parameters---of what is called a scale-invariant power which is a prediction of standard inflation models irregardless of the details of the inflation mechanism (CL-263,265,274--275; Gr-309).
The fact that inflation predicted the observations is an astonishing triumph of the inflation paradigm.
The successful prediction does NOT prove inflation, but it certainly strongly supports it.
Credit/Permission: NASA,
WMAP Science Team,
2006
(uploaded to Wikimedia Commons
by User:Pieter_Kuiper,
2007) /
Public domain.
Image link: Wikimedia Commons:
File:PowerSpectrumExt.svg.
Local file: local link: cmb_power_spectrum.html.
File: Cosmology file:
cmb_power_spectrum.html.