Employability

Employability is basically the ​skills and ​abilities that ​allow you to be ​employed

Many employers across all industries want more than just a degree; they want graduates who can demonstrate a wide range of those skills, attributes and knowledge. Being able to demonstrate your ES, as well as work experience, volunteering and general experiences all enable you to become more employable.

‘a set of achievements – skills, understandings and personal attributes – that make graduates more likely to gain employment and be successful in their chosen occupations, which benefits themselves, the workforce, the community and the economy’

Professor Mantz Yorke (2004) 'Employability in Higher Education: what it is - what it is not', Higher Education Academy/ESECT

Sources:http://www.dictionary.com/browse/employability
http://www.employability.ed.ac.uk/What/https://en.wikipedia.org/wiki/Employability

Workability

The concept of workability is that it's about something capable of being worked, dealt with, or handled.It is also used to say "Degree of ease by which a material can be cut, shaped, or smoothed by hand or machines", in that case classifying some sort of material that can be worked with.

Basically,"workability" means that something/someone can learn how to be or simply be suitable for a certain situation.

Sources:

 http://www.dictionary.com/browse/workability

http://www.businessdictionary.com/definition/workability.html