WRB excellent job explaining about rods. The power tells you about the amount of backbone and helps in understanding the rod and its lure rating. The action tells you how easy or how far the rod will bend. Certain techniques work best with certain power and action combinations. Now please understand I have fished since I was a young boy and most of all of the first 10 years I used 1 or two rods. Many people have one rod and are thrilled with that method. If I were to go that way again it would be a medium action spinning rod probably 7 foot long.
Now I own 1 or 2 rods that best allow me to fish each specific lure type. So I have jig & plastics rods, crankbait rods, a frog rods etc. This makes me more efficient, but causes me to have an overstuffed rod locker. LOL
Let's look at 2 of the most common baitcasters. The first is a 7 foot medium power moderate action and the second one is a 7 foot medium power fast action rod. Both usually cast 1/4 to 3/4 ounce lures. The medium-moderate rod will usually bend all the way down from the tip guide all the way down to the 4th or 5th guide. This means it will load well and cast maybe bulkier baits, but more importantly it will "give" and absorb a fish's runs better, so lures with treble hooks like crankbaits and rattle traps will stay buttoned up. Many of the fish we loose with treble hook baits are lost because we use faster action rods that react quicker so sometimes the bass gets a little slack and poof your fish is gone. The moderate action rod bends further down the blank and reacts slower. Now the medium power fast action rod will usually bend only down say to the 2nd or 3rd guide. If you are fishing bottom bouncing baits where you hop a bait or slowly swim a bait then the faster action rod helps deliver the power quicker and offers more sensitivity. Lures such as rattle traps, crankbaits, topwaters, jerkbaits, and both spinnerbaits and chatterbaits all work best on slower action rods. We usually use fast or extra fast action rods for jigs, texas rigged plastics, carolina rigs, and even frogs. Rod powers are often chosen to allow us to throw lures by the lures resistance in the water and their weight. For example the rod I throw my 1/4 to 3/8 spinnerbaits is a 6'6" medium power moderate action baitcasting rod. If I want to throw a big 3/4 to 1 ounce spinnerbait I would use my 7 foot medium heavy moderate action rod. They have the same action or taper (just another name to confuse you but means the same as action for our purpose)but have different powers thus the lure weights they cover are different. I hope that helps.
Now if we look at the three spinning rods I carry here is a good example. I carry two identical G Loomis 6 foot IMX rods. The first is a 6 foot light power rod that handles baits that weigh 1/16 to 5/16. My other 6 foot is a medium power rod that handles baits that weigh 1/8 to 3/8. They may seem to cover many of the same lures but the rods act very differently. I can easily throw Ned rigs ( a 1/10 ounce jig with a special 3 inch piece of worm) grubs and small baits like mepps spinners on the light power rod. The medium rod has enough backbone to hook a fish using larger plastics, and heavier baits. My third rod is a 7 foot medium that has a faster tip and more backbone. It can toss lighter baits further distance due to its longer length, It also has more backbone so I can hook a fish further out or in deeper water.
Here is a quick guide to reel ratio uses. For baits like frogs, or techniques like pitching a jig in heavy vegetation I use a higher speed reel, usually 8-1. For baits like spinnerbaits and buzzbaits if I want to burn it up near the surface I like a 7-1. For regular spinnerbait fishing, small crankbaits, squarebills, jigs, texas rigs, carolina rigs, rattle traps, hollow bodied swimbaits etc. I like a 6.3-1 reel. And for deep diving cranks like DD22s or other crankbaits that dig their way down to 15 foot or deeper than a 5.3-1 or so is best.
