What is the base peak in mass spectrometry?

In mass spectrometry, the most intense (tallest) peak in a mass spectrum is known as the base peak, and is seen along the spectrum's y-axis. The base peak occurs due to the ion with the greatest abundance or relative intensity. The base peak is typically given an intensity value of 100 and the intensities of other peaks are expressed as a percentage of the base peak intensity. The ion is most abundant and stable at this point, which is useful for identification of the compound. It is important to note that the base peak is not always the peak corresponding to the molecular weight of the compound being analyzed. The base peak is only a measurement of the most intense peak amongst other peaks that arise from fragmentation and ionization processes in the mass spectrum.