That's the same thing I think. Except, the first year you buy CD's that are 1, 2, 3, 4 and 5 years. Each of the 2nd through 4th years you buy a 5 year CD with the money from the CD that matured that year. That way each year you buy one 5 year CD at whatever the interest rate is that year. Otherwise you're not getting much (if any) return on 80% to 20% of your money in years 1 - 4. Say you had $50,000, if my math is correct you'd earn $1,200 more buying the short term CD's the first year rather than waiting and buying a 5 year CD each year. You could also buy five $10,000 CD's but the risk to doing that is interest rates jump up (inflation?) and you're stuck with all your money at the lower rate.
Assuming you don't need the entire amount if you have five CD's you can limit your exposure to penalties by only withdrawing what you need. (Six months interest, at 2.5% on $50,000 would be $628 vs. $125 on $10,000)

if that's significant or not.