What are Timing Libraries?

A library file is made of not only a list of gates but also contain the following

• Functional or Logical definitions of the each gates
• Power, energy characteristics for each inputs of the gate
• Timing characteristics for delay of the gate
• Physical characteristics which represents the area and footprint of the gate
• Same gate is define by the different characteristics with different attributes of area, timing and power

When this timing library is given as an input to a synthesis tool along with the RTL code which is in the behavioral form, it converts it into the structural design.

Synthesis can replace gates with other gates of the same footprint without affecting the functionality for meeting the constraints of the design