The field of synthetic biology is evolving so quickly that there are multiple definitions for the field. Among them:
Synthetic biology is a) the design and construction of new biological parts, devices and systems and b) the re-design of existing natural biological systems for useful purposes.
Synthetic biology is an emerging area of research that can broadly be described as the design and construction of novel artificial biological pathways, organisms or devices, or the redesign of existing natural biological systems.
Two of the best explanations of the field are the following videos:
The above definitions are useful because they emphasize design and construction, because in the beginning biotechnology was an artisanal skill, rather than a science. The definitions emphasize the redesign of existing biological systems because nature has given us a toolset.
But that existing biotech tool set – the one biotechnology has used for the first 50 years of its history – is not adequate for the design and construction of new, predictable and reproducible systems for useful purposes.
For our purposes, we will simply define synthetic biology as a movement to “make biology easier to engineer.”
Image source: Jakob Schweizer, The Toolbox of Life