2. Direction
A direction is angle from a meridian to a line. It is similar to a horizontal angle in a traverse except the backsight is always along the meridian, Figure C3.
Figure C3 
There are two different ways to express line direction: bearing and azimuth.
a. Bearing
A bearing is an angle from the North or South end of the meridian turned to the East or West. A bearing has three parts:
 Prefix  N or S indicating which end of the meridian is turned from.
 Angle
 Suffix  E or W indicating turning direction from the meridian to the line.
N 66°40' E  from the North end of the meridian, turn 66°40' to the East.
Example
Bearing AB = N 66°40' E Bearing AC = S 55°32' E Bearing AD = S 44°21' W 

Figure C4 Bearings 
A bearing falls in one of four quadrants so the angle does not exceed 90°. The angle is to the right (clockwise) in the NE and SW quadrants, to the left (counterclockwise) in the SE and NW quadrants. A due North direction can be expressed as either N 00°00' E or N 00°00' W; due East as N 90°00' E or S 90°00' E; similarly for dues South and West.
A backbearing is reverse of a bearing, that is, Bearing BA is the backbearing of Bearing AB. Because the meridians are parallel at both ends of the line, the bearing angle is the same but quadrant is reverse. This is true only when meridians are parallel. Where meridians converge, the forward and back bearing angles will differ by the total convergence. More on this later.

Bearing AB = N 66°40' E

Figure C5 Back Bearing 
b. Azimuth
An azimuth is an angle to the right (clockwise) from the meridian to the line. In most cases the azimuth is turned from the north meridian end; earlier control surveys used the south end. An azimuth varies from 0° to 360°.
Example
Azimuth AB = 66°40' Azimuth AC = 124°28' Azimuth AD = 224°21' Azimuth AE = 322°26' 

Figure C6 Azimuths 
A backazimuth is reverse of a azimuth: Azimuth CA is the backazimuth of Azimuth AC. Because the meridians are parallel at both ends of the line, the backazimuth and forward azimuth differ by 180°. As with bearings, this is true only when meridians are parallel. Where meridians converge, the forward and back azimuths will differ by (180° ± total convergence). More on this later.
Example
Azimuth AC = 124°28' Azimuth CA = 124°28' + 180°00' = 304°28' 

Figure C7 
c. Converting Between Bearings and Azimuths
Since Bearings and Azimuths are both referenced to a meridian it is simple to convert one to the other.
To convert from bearings to azimuths:
Table C1  
Quadrant  From Bearing  To Azimuth 
NE  N β E  β 
SE  S β E  180°  β 
SW  S β W  180° + β 
NW  N β W  360°  β 
Example
Azimuth AB = 66°40' Azimuth AC = 180°00'  55°32' = 124°28' Azimuth AD = 180°00' + 44°21' = 224°41' Azimuth AE = 360°00'  37°34' = 322°26' 

Figure C8 Azimuths from Bearings 
To convert from an azimuth, α, to a bearing:
Table C2  
Quadrant  To Bearing 
NE 
N α E 
SE 
S (180°  α) E 
SW 
S (α  180°) W 
NW 
N (360°  α) W 
Example
Bearing AB = N 64°40' E Bearing AC = S (180°00'124°28') E = S 55°32' E Bearing AD = S (224°21'  180°00') W = S 44°21' W Bearing AE = N (360°00'  322°26') W = N 37°34' W 

Figure C9 
Rather then memorize tables, drawing a sketch will help determine correct conversion logic to use.
d. Bearing or Azimuth?
Which one should a surveyor use to express directions? It shouldn't matter as both express the same thing abeit using a different format.
The bearing's biggest advantage is that it's immediately recognizable as a dirrection: N 24°18'30"E, S 56°05'24"W. An azimuth, on the other hand looks like an angle (which it is) with no indication what it represents unless it's specifically called out as a direction: 242°45'36" vs 242°45'36" Az.
Bearings are a more traditional way of expressing directions, espacially in property surveys. Check any metes and bounds description or subdivision plats and chances are 10 times out of 9 the bearings will be used for directions.
Azimuths have a computational edge. Bearing angles are limited to a maximun of 90° and can be clockwise or counterclockwise measured from either end of the meridian. Azimuths always start from North and are clockwise. As we'll see shortly, that makes them easier to compute going around a traverse. And we'll see later how azimuths are a little more efficient for other traverse computations.
So which direction format to use is basically up to the surveyor.