Here's some more info. This will really help you understand the different positions in football. (or soccer, whatever, I can't get used to that word
):
Goalkeeper
The goalkeeper is the most specialised position in football. His job is purely defensive: to guard his team's goal from being breached, and as such he is allowed to use his hands when playing the ball. The discipline of goalkeeping is so specialised that it is virtually unheard of in the professional game for a goalkeeper to play in any other position. Occasionally, a goalkeeper will temporarily become an extra striker if his team is a goal behind in a game they must win, and the team has a corner or free-kick in an attacking position. In such a situation, the goalkeeper's defensive duties can safely be ignored as a defeat by two goals is no worse than a defeat by one. One goalkeeper in recent times who was famous for taking free kicks, even in situations where his team was not trailing, was José Luis Chilavert. If a goalkeeper is sent off or injured, and there is no substitute goalkeeper available, then an outfield player will take his place.
Goalkeepers are almost invariably tall and physically strong in order to claim the ball more easily. They must be agile and have excellent reactions to stop shots, and have good positional sense and decision-making in order to be in the right place to gather the ball. The standard football skills of ball control, tackling, passing and pace are not usually required in a goalkeeper, although the rule change that now means a goalkeeper may not handle the ball when it is passed back to him has led to goalkeepers practising their control and dribbling to a greater extent than before.
Goalkeepers of renown
Gordon Banks
Dino Zoff
Lev Yashin
Defensive positions
Centre back
The job of the centre backs or central defenders is to stop opposing players, particularly the strikers, from getting the opportunity to score, and to clear the ball from their own penalty area. As their name suggests, they play in a central position. Most teams employ two or three centre backs, in order to double-up coverage against an opposing attacker. There are two main defensive strategies used by centre backs: the zonal defence, where each centre back covers a specific area of the pitch, and man-to-man marking, where each centre back has the job of covering a particular opposition player.
Centre backs are usually tall, with good heading ability, strong and brave in the challenge and able to tackle well. An ability to read the game well is a distinct advantage. Traditionally, centre backs have concentrated less on ball control and passing, preferring to punt the ball off the pitch or upfield, in a "safety-first" fashion. Recently, however, it has become more common for centre backs to have more than just rudimentary footballing skill, as this enables a calmer, more possession-orientated style of play. The stereotypical centre back is slow and lumbering, although in recent years this has changed as the pace of the game has increased.
The position is sometimes referred to as centre half. In the early part of the 20th century, when most teams employed the 2-3-5 formation, the row of three players were called half backs. As formations evolved, the central player in this trio (the centre half), moved into a more defensive position on the field, taking the name of the position with him.
Centre backs of renown
Bobby Moore
Sweeper
The sweeper is a more versatile type of centre back that "sweeps up" the ball if the opponents have managed to breach the defensive line. He is usually used in a three-man back formation together with two man-to-man marking centre backs. The sweeper is also expected to build attacking moves, and as such requires greater ball control and passing ability than a typical centre back. The sweeper's ability to read the game is even more vital than for a centre back.
The position is often referred to as libero (from the Italian: free), as he is free to rove up and down the field, in contrast to the man-to-man markers, who must stick close to their designated attacker. The catenaccio system of play, used in Italian football in the 1960s, popularised use of the sweeper.
Sweepers of renown
Franz Beckenbauer
Full back
The full backs take up the wide defensive positions, one on each side of the field. Their main task is to prevent opposition players crossing the ball into the penalty area. Most full backs are also expected to provide an attacking dimension by getting upfield along the wings and providing crosses of their own.
The traditional full back in (the "2" in the 2-3-5 formation) was a strong, slow player, but the modern full back is usually short, agile and pacy, strong in the tackle and with good stamina to enable him to get up and down the field.
Full backs of renown
Roberto Carlos
Paolo Maldini
Wingback
The wingback is a modern variation on the full back with a heavier emphasis on attack. They are usually employed in a 3-5-2 formation, and could therefore be considered part of the midfield. As the role combines that of the winger and the full back, wing backs are blessed with great stamina. As they have the support of three centre backs, they are expected to concentrate more on providing crosses for their strikers and less on their defensive duties.
Midfield positions
Centre midfield
Central midfielders play a number of roles on the field of play, depending on their particular strengths and weaknesses and the tactics of the team. They are the link between defence and attack when their team is in possession of the ball, and must also defend when the opposition are in possession. Their central position enables them to have an all-round view of the match, and as most of the action takes place in their area of the pitch, it is the midfielders who can exert the greatest degree of control over how a match is played.
Central midfielders are often divided into defensive and attacking midfielders. A defensive midfielder will share many characteristics with a centre back, but must have a greater ability to keep possession and use it effectively. An attacking midfielder will be expected to make runs into the opposition penalty area and try to score goals. All midfielders need excellent fundamental footballing skills, i.e. good ball control and passing. In addition, they should be strong in the tackle and have good stamina, and perhaps most importantly, the vision and awareness to spot and pass to team-mates in a good position. Of all the positions, midfield is the one where raw speed is least important, as this can be compensated for by ability on the ball.
A central midfielder who is particularly good at controlling the tempo of a match is often referred to as a midfield general.
Central midfielders of renown
Bobby Charlton
Michel Platini
Zinedine Zidane
Winger
The out-and-out winger is a position that has been less fashionable since Alf Ramsey's England side — the "Wingless Wonders" — won the World Cup in 1966. The role has been absorbed into right and left midfield, or taken over by full backs or wing backs. However, many outside midfielders can still legitimately be classed as wingers.
The job of the winger is simply to provide crosses into the penalty area for the strikers to score from. Traditionally this was done using lightning pace and/or great dribbling ability in order to beat the opposing full back, get past him and deliver the ball into the danger area. Wingers were not expected to contribute to the defence.
The modern game tends to expect its players to be more versatile, and midfielders are expected to perform a defensive role as well as an attacking one. Despite this, the left and right midfielders are still there to provide crosses.
Wingers of renown
Tom Finney
Garrincha
Stanley Matthews
Attacking positions (strikers)
Centre forward
The centre forward has one main task: to score goals. Despite the one-dimensional nature of the job description, there two main types of centre forward: the "target man" and the "link man". Most teams that play with two strikers will field an attacker of each type.
Target men are usually of above average height, with good heading ability, a powerful shot and the ability to "tell where the goal is". The target man will tend to score goals from crosses, often with his head, and will use strength to muscle defenders off the ball or shield the ball with his back to goal while he waits for a team-mate to pass to.
Link men are often smaller in stature, with excellent dribbling skills and good pace. Although they are expected to contribute goals, their role is mainly to create chances for the target man.
Smaller strikers tend to prefer to use their pace to run onto a ball passed over or behind the opposition defence, rather than to collect the ball with their back to goal in the manner of a target man.
Centre forwards of renown
George Best
Johann Cruyff
Diego Maradona
Gerd Müller
Pele
The "hole"
The "hole" is the name given to a loosely-defined position somewhere between the out-and-out striker and the midfield. The hole player is usually a skilful, attack-minded midfielder who can both score himself or create opportunities for a centre forward. As such it is quite a specialised position that relatively few players can successfully fill. A good hole player can cause problems for the opposition as his unorthodox position can leave them undecided as to whose job it is to cover him. This creates space and time that the "man in the hole" can exploit.
"Hole" players of renown
Dennis Bergkamp
Ronaldinho
Pablo Aimar