One the best text that I read about tactics, combinations, positional and good movements in chess is in the excellent book: MASTERING CHESS A COURSE IN 21 LESSONS – by G. Chandler -  D. Kopec – C. Morrison – N. Davies – I.D. Mullen. See below:

Tactics 

This is the term given to the hand-to-hand fighting which takes place on the chessboard when the opposing pieces come into direct contact with each other, i.e. attacking and defending. Basically, a tactical move involves a threat, or a series of threats, to which the opponent must respond immediately. It is normally a forcing sequence, and thus the number of replies is generally limited.

Combination

A combination is a series of tactical moves played in order to gain an advantage (or lessen or neutralize a disadvantage).  It may span anything from one to more than fifteen moves.

There are four main types of combination:

1.       The mating attack.

2.       The material gain combination.

3.       The positional combination.

4.       The drawing combination.

These classifications contain many “tricks of the trade” which form the bulk of all chess players` armory. A “tactical tree” has been drawn up to aid student, giving a list of all the main tactical motifs that are discussed here (in this book).

A good chess move

A good chess move will fall into one of the following three categories:

1.       Tactical (as defined above).

2.       Strategical (deploying one`s forces, following an overall plan, maneuvering etc.).

3.       Forced (getting out of check, recapturing a piece).

It should be noted that mating attack and material gain combinations are closely linked and the ideas used in a material gain combination can be (and very frequently are) used to mate the enemy king.

Positional

Positional combinations are played to increase the scope of one`s pieces, laying the ground work for a future material gain or mating combination.

Drawing combinations speak for themselves and give the tactically acute player a chance of snatching lost games from the fire.

Table 1. A “Tactical Tree” giving a List of Tactical Motifs Found in Combinations