We report a detailed comparison between RF and microwave (HF) plasmas of N-2 and Ar-20 %N-2 as well as in the corresponding afterglows by comparing densities of active species at nearly the same discharge conditions of tube diameter (5-6 mm), gas pressure (6-8 Torr), flow rate (0.6-1.0 slm) and applied power (50-150 W). The analysis reveals an interesting difference between the two cases; the length of the RF plasma (similar to 25 cm) is measured to be much longer than that of HF (6 cm). This ensures a much longer residence time (10(-2) s) of the active species in the N-2 RF plasma [compared to that (10(-3) s) of HF], providing a condition for an efficient vibrational excitation of N-2(X, v) by (V-V) climbing-up processes, making the RF plasma more vibrationally excited than the HF one. As a result of high V-V plasma excitation in RF, the densities of the vibrationally excited N-2(X, v > 13) molecules are higher in the RF afterglow than in the HF afterglow. Destruction of N-2(X, v) due to the tube wall is estimated to be very similar between the two system as can be inferred from the gamma(v) destruction probability of N-2(X, v > 3-13) on the tube wall (2-3 x 10(-3) for both cases) obtained from a comparison between the density of N-2(X, v > 3-9) in the plasmas to that of the N-2(X, v > 13) in the long afterglows. Interestingly enough, densities of N-atoms and N-2(A) metastable molecules in the afterglow regions, however, are measured to be very similar with each other. The measured lower density of N-2 (+) ions than expected in the HF afterglow is rationalized from a high oxygen impurity in our HF setup since N-2 (+) ions are very sensitive to oxygen impurity .