Using first principles approaches, the structural, electrical, elastic, and magnetic characteristics of L21 structured Co2VZ (Z= Si, Ge) complete Heusler alloys with space group Fm-3m and half-Heusler CoVZ (Z= Si, Ge) compounds with space group F-43_m were examined. The full potential linearized augmented plane wave (FP-LAPW) approach, as implemented in WIEN2k, is used here. Co2VSi exhibits zero band gaps in both the majority and minority spin channels, whereas Co2VGe exhibits a finite band gap of 0.668 eV in the minority spin channel and zero band gaps in the majority spin channel around the Fermi level implemented in the WIEN2k code, exhibiting 100% spin polarization. As a result, Co2VGe is discovered to be perfectly half-metallic ferromagnetic (HMF), whereas Co2VSi is metallic in nature. In both spin channels, CoVZ (Z= Si, Ge) compounds exhibit semiconducting behavior. Co2VZ (Z= Si, Ge) compounds have computed magnetic moments of 3.04 and 3.01 B, respectively, whereas CoVZ (Z= Si, Ge) compounds have zero magnetic moment. Here, we see that the code's and Slater-Pauling rule's estimated results have good tuning. Pugh's ratio B/G values are more than 1.75 for all ductile compounds except CoVGe, which is brittle in nature. Because a positive value of Cauchy pressure (CP = C12 - C44) indicates ductile nature and a negative value indicates brittle nature, we can conclude that all compounds are ductile except CoVGe, which is brittle. Pugh's ratio and Cauchy pressure both produce similar results.