Inelasticity–the fraction of a neutrino ’ s energy transferred to hadrons–is a quantity of interest in the study of astrophysical and atmospheric neutrino interactions at multi-TeV energies with IceCube . In this work , a sample of contained neutrino interactions in IceCube is obtained from 5 years of data and classified as 2650 tracks and 965 cascades . Tracks arise predominantly from charged-current \nu _ { \mu } interactions , and we demonstrate that we can reconstruct their energy and inelasticity . The inelasticity distribution is found to be consistent with the calculation of Cooper-Sarkar et al . across the energy range from \sim 1 TeV to \sim 100 TeV . Along with cascades from neutrinos of all flavors , we also perform a fit over the energy , zenith angle , and inelasticity distribution to characterize the flux of astrophysical and atmospheric neutrinos . The energy spectrum of diffuse astrophysical neutrinos is well-described by a power-law in both track and cascade samples , and a best-fit index \gamma = 2.62 \pm 0.07 is found in the energy range from 3.5 TeV to 2.6 PeV . Limits are set on the astrophysical flavor composition that are compatible with a ratio of \left ( \frac { 1 } { 3 } : \frac { 1 } { 3 } : \frac { 1 } { 3 } \right ) _ { \oplus } . Exploiting the distinct inelasticity distribution of \nu _ { \mu } and \bar { \nu } _ { \mu } interactions , the atmospheric \nu _ { \mu } to \bar { \nu } _ { \mu } flux ratio in the energy range from 770 GeV to 21 TeV is found to be 0.77 ^ { +0.44 } _ { -0.25 } times the calculation by Honda et al . Lastly , the inelasticity distribution is also sensitive to neutrino charged-current charm production . The data are consistent with a leading-order calculation , with zero charm production excluded at 91 \% confidence level . Future analyses of inelasticity distributions may probe new physics that affects neutrino interactions both in and beyond the Standard Model .