Positional chess involves accumulating posiional strengths (such as a good pawn structure, good bishop, or mobile pawn majority on one flank) while forcing positional weaknesses (such as doubled or isolated pawns, or a bad bishop) on your opponent. The contrast with tactical chess is impure because positional objectives are often achieved by tactical means.
Positional Chess

I like chyss' answer, especially about how tactics and positional ideas are interwoven and you can't separate them.
Maybe another way to say it is when playing for a positional advantage you're increasing the strength of your pieces by playing against some static (read: not short term) weakness in your opponent's position. A tactic often completely disappears in 1 move if you miss it. But a weakness in pawn structure, immobile pieces, weak color complex or an unsafe king take a long time (if ever) to fix.

You can read all about it, but you probably wont see it for yourself until the game feels a little less random. At lower levels there is this sense that anything can happen... at any moment a player may lose a pawn or knight to an unseen tactic or a rook or bishop sniping from across the board.
When you're good enough to avoid all the tactics in a quiet position you'll start to have games where the material is even... but move after move for some reason your position feels really bad. Your opponent has so many options, but all your pieces feel stuck or passive and you can't make a threat.
That's what it feels like to be positionally lost.

leiph15 wrote:
You can read all about it, but you probably wont see it for yourself until the game feels a little less random. At lower levels there is this sense that anything can happen... at any moment a player may lose a pawn or knight to an unseen tactic or a rook or bishop sniping from across the board.
When you're good enough to avoid all the tactics in a quiet position you'll start to have games where the material is even... but move after move for some reason your position feels really bad. Your opponent has so many options, but all your pieces feel stuck or passive and you can't make a threat.
That's what it feels like to be positionally lost.
Me to a t.

Following general rules can help get you to a decent mid game position most of the time. Don't capture without a good reason (first idea should be to defend or ignore). Try to place and then try to keep a pawn in the center. Don't move the space piece twice. Don't attack without finishing development. Castle. Limit pawn moves in the opening (want to bring knights and bishops out as fast as possible). These kinds of things.

There is the analogy with the goose. Positional chess is the cooking of the goose. Tactics come in when you want to eat it.

I view it as using heuristics (= rules of thumb) more than tactics (= specific move-by-move emphasis). Yes, positional versus tactical are roughly opposites.

Positional chess is more in opposition to attacking chess than tactics, although like every sound bite generalisation that is far too much of a simplification.
Obviously positional players (or players using positional ideas in their games) still attack, but they are maybe more likely to do so when they have their army all primed and ready. Pure attacking players are probably more likely to look for a piece sacrifice to blast open the king and pile in, the better players with a plan, lesser players often just off the back of a speculative sacrifice.
As I said, that is too much of a simplification though really. A good player will combine all aspects of chess into his game, just favouring some slightly more than others.
Another example in addition to those above that is a positional concept is the question of where you put your knights. Knights like outposts, holes, squares that are defended by their own pawns and ideally cannot be attacked at all by an enemy pawn. It is a positional concept to actively try to create such outposts for your Knights rather than just fling them into an attack or purely look for forking opportunities.

Capablanca was called the chess machine. By rights therefore he should have sucked at positional chess.

It is sometimes thought that Capablanca was not that good at tactics. He reinforced the idea one day when asked how many moves ahead he saw. He said: "One". For all those positional gurus out there, what is the use of cooking your goose if you don't know how to eat it?

If you can say for some reason that your chances are better than your opponent's, even though you are not material ahead, you are claiming a positional advantage (you are claiming that your goose is cooking nicely).

I may be wrong, but I suspect the levels of complexity involved in cooking a goose are slightly less than those in a game of chess.
What is meant by positional chess ? Is it in opposition to tactical chess and how?