Once you have created an IR spectrum, you need to interpret it. Two ways that this can be done is to examine the spectrum using an IR absorbtion table, which has been compiled through the years, or compare the spectrum to a library of spectra, assuming, of course, that the spectrum you want to compare has been taken and put in the library for comparison.
In the Vinyl Alcohol example, you will see how the spectrum and the chart represent the molecule in question. When viewing the page notice how some peaks are partially covered by other, more prominent peaks. Also one of the bond could be in an entire range. Infrared spectrum are not infallible. They can give a lot of useful information. However, if you do not have an idea of what you are looking for (at the very least a chemical formula e.g. C6H14) all you will have is possibilities of molecule parts. Additional tests, such as NMR, are extremely useful in conjunction with IR to create a more whole picture.