Consider the situation where you might be hired based on the look of your composite card or portfolio, and you show up with a completely different hairstyle and color of hair. Hopefully the ongoing jobs and testing you do with photographers will give you a constant supply of new photos. Again, make sure that if you change your look to get new photos right away. Composite cards go by many different names. Because of the difference in german and english pronouciations, Seds became known as Zeds.
Composite cards are miniature portfolios which are mass produced.
If the model has particularly good features or special talents, that is also often listed on the composite card. Most comp cards are black and white, however, many from larger agencies are in full color. As with portfolio photos, models are responsible for paying for their own composite cards. When you are starting out, 100-200 is a good number to order. You can always get more in the future if you run out.