Observations of protons, alpha particles, and medium group nuclei (C,N,O) have been made with particle counters aboard the IMP 7 and 8 (Explorer 47 and 50) spacecraft for the time period from October 1972 to the present. Since this interval includes nearly the complete solar cycle 21, and the data coverage is high, it is now possible to characterize the entirety of solar and interplanetary particles in the vicinity of the earth. Extensive and detailed catalogs of identified solar flare events have been prepared for two periods of time, classified as Solar Minimum (day 300 to 1974 through day 200 of 1977) and Solar Active (day 1 of 1978 through day 365 of 1981). Histograms of daily averaged particle fluxes have been prepared for three types of subintervals of the Solar Minimum and Active periods. These subintervals were for flare particle-dominated times, quiet times, and the residual (nonflare, nonquiet). Comparison of these histograms yields a variety of salient differences between the compositions and intensities of particles in these subintervals. During Solar Minimum, for example, each type of subinterval displays distinctly different compositions both in the median and in the distribution, with flare times showing by far the greatest variability of proton/alpha and alpha/medium ratios. During Solar Active time there does not appear to be a compositionally distinct signature of flare times as compared to nonflare, nonquiet times. We discuss and characterize these results and other quantitative measures of solar and interplanetary charged particle fluxes in solar cycle 21.