The many pointed nibs are differentiated (apart from by their shape) by their flexibility and the fineness of their nib tip.

A pointed nib usually produces a slightly finer stroke than a ball point nib. However, more skill is required for its use.

When the nib is pulled pressure can be applied to adjust the thickness of the stroke. The more flexible the nib, the greater the range of thickness. But more flexibility also enlarge the nib's sensitivity to wrongly applied pressure; that is to say, when the nib is pushed under pressure.

See this Video about the use of flexible and pointed nibs:

To describe the flexibility of the nibs, I use the following terms:  

• Extremely flexible
• Very high flexibility
• High flexibility
• Medium flexibility
• Little flexibility
• Hardly flexible
• Not flexible