What is Stereolithography?
Stereolithography has many names and few of them are 3D layering, 3D printing, solid free-form fabrication, photo-solidification and solid imaging. It is the most common and extensively used form of rapid manufacturing and rapid prototyping. Stereolithography fabricates 3D parts and allows creating solid 3D objects from CAD models with high precision and excellent surface finish within few hours (time depends upon size and complexity). Machines used for Stereolithography are known as Stereolithography Apparatus (SLA).

Advantages and Disadvantages:
Stereolithography provides a quick and simple means to convert CAD models into real objects. This is very useful where time is money. The constraint as mentioned above is that the time to produce three dimensional parts depends upon the size and complexity of the object. The accuracy is very good having tolerance within .004"/inch. The problem again is that SLA devices or machines are too expensive. Photo-curable resin used in Stereolithography can cost as high as $800 per gallon. Then the process involved in SLA produces fumes due to which it requires a well ventilated environment

Best Part of Rapid Prototyping:
Since 1986, the year of its invention, SLA has taken large steps equally in its machine design and resources used for it. SLA is real rapid modeling and is fast switching from rapid prototyping to rapid manufacturing. It can be an exceptionally convenient and valuable process in many conditions and for many industries. It has been used effectively to aid surgeons with ear implants and can be used in almost every industry from jewellery manufacturing to military, power, marine etc. This makes it the best part of rapid prototyping.