What is a fishing reel
A reel does three things: it holds a stock of line, feeds it out on the cast, and gives it back under load when a fish pulls harder than the tackle will take. The third job is the important one, and the drag is what does it.
Three types, and one difference between them
The whole classification rests on whether the spool turns during the cast. On a spinning reel the spool is fixed and the line comes off it in coils over the lip. On a baitcaster and on a centrepin the spool rotates, paying out line turn by turn.
From that single difference follow the casting distance, the tendency to tangle, and which hand turns the handle.
The drag is the critical part
The drag is a brake that lets the spool slip once the pull exceeds a set figure. Adjusted properly it gives before the line reaches its limit, and the fish takes metres instead of breaking the tackle.
You check it at home rather than on the water: pull the line off by hand. It should come evenly, without jerks and without jumps in effort.
Gear ratio
A figure such as 5.2:1 says how many turns the rotor makes for one turn of the handle. A higher number means faster retrieve and less effort per turn at the handle; a lower one means a slower retrieve but more confidence under a heavy load.
Retrieve speed does not depend on the ratio alone: a full spool takes in more line per turn than an empty one.
Size: a number that is not a standard
Size is given as a number — 1000, 2500, 3000, 4000. It describes the bulk and capacity of the spool, but there is no single standard between makers: a 2500 differs from brand to brand. Go by the stated capacity in diameter and metres, not by the number itself.
How much line to load, and why the spool should sit almost level with the lip, is covered separately in how to choose fishing line.
Which side the handle goes on
On a spinning reel the handle swaps to either side: it screws into a through spindle and the opposite side takes a blanking cap. So a left-hand and a right-hand model are the same reel assembled differently.
A baitcaster does not allow this: there the handle is tied to the gearing, and the side is chosen once, at purchase.
Maintenance
A reel is not stripped without cause, but it is rinsed after every exposure to salt water and wiped down after rain. Sand that gets under the rotor wears the bearings faster than any fish ever will.
In cold weather heavy grease thickens and the reel turns stiffly — that is not a fault. For the rest of the tackle and the same routine, see the fishing rods section.
What we do not write here
We do not compare brands or recommend models: ranges are replaced every year. Nor do we quote bearing counts as a measure of quality — that number is easy to raise without improving the reel.