Congenital Diaphragmatic Hernias are divided into two groups:
Posterolateral (Bochdalek)
OR
Non-Posterolateral (non-Bochdalek)
In medical terminology, "posterior" refers to the back. It's opposite is "anterior", meaning front. "Lateral" refers to the side. So "posterolateral" would be a defect involving absence of the diaphragm along the back and side.
The diaphragm is a dome-shaped muscle, almost like a parachute in shape. Its two halves are joined by a ligament in the center. Each half of the diaphragm may be referred to as the right diaphragm or left diaphragm. You will hear CDH commonly referred to as "left-sided CDH" or "right-sided CDH", in reference to which side of the diaphragm the hernia is located in and which abdominal organs have herniated through it.
Illustration of a Normal Diaphragm

(http://healthguide.howstuffworks.com/diaphragm-picture.htm)
Normal Diaphragm

(http://www.ncbi.nlm.nih.gov/bookshelf/br.fcgi?book=gene&partid=1359&rendertype=figure&id=cdh-ov.F1)
[Pober et al 2006], "Posterolateral (Bochdalek) hernias comprise approximately 80-90% of all CDH and appear to fall into two types: a) a diaphragmatic defect accompanied by absent or extremely deficient rim of posterior and lateral musculature (see Figure 2a); and b) a diaphragmatic defect with an intact rim of posterior and lateral musculature. About 85% of Bochdalek hernias occur on the left side, about 10% on the right, and approximately 5% are bilateral."
Types of CDH

(http://www.ncbi.nlm.nih.gov/bookshelf/br.fcgi?book=gene&partid=1359&rendertype=figure&id=cdh-ov.F2)
The Non-Posterolateral, or non-Bochdalek hernias are diaphragmatic hernias involving the anterior (or front) or central portion of the diaphragm (see figure above). Non-Bochdalek hernias are further broken down into subtypes.
1. Morgagni (Morgagni-Larrey) hernia - Morgagni hernia is an anterior hernia near the sternum that can result in the herniation of liver or intestines into the chest cavity (see Figure 2b). 2% of all CDH are Morgagni hernias. These hernias frequently do not cause symptoms in the newborn period.
2. Other anterior hernias associated with Pentalogy of Cantrell - These rare and severe types of hernias are found in individuals with Pentalogy of Cantrell (which also includes defects in the supraumbilical midline abdominal wall, lower sternum, diaphragmatic pericardium, and heart).
3. Central hernia - This hernia is a rare diaphragm defect involving the central tendinous (e.g., amuscular) portion of the diaphragm. The entire rim of diaphragmatic musculature is present (see Figure 2c). [Pober et all 2006]
Most of the time, when discussing CDH on this site, I'll be referring to Bochdalek hernias, either right-sided (RCDH) or left-sided (LCDH), unless otherwise specified, since these are the most common type. The GeneReviews article on the Links and References pages was heavily referenced in this post. Please check it out for further details.