Answer: While both measure resources, one is focused on algorithms to measure resources.
The meaning changes when the subject changes .The difference is that one refers to the algorithms and another can refer to resources used (if we talk about administration as in the example).
Explanation:
An example outside of computer science in which you have heard the term efficiency :
Efficiency is the ability to have something to achieve proper fulfillment of a function. For example, in administration, efficiency can be defined as the relationship between the achievements made with a project and the resources used in it.
The way we talked about efficiency in programming :
The term efficiency is used to describe those properties of algorithms that are related to the amount of resources used by it. An algorithm must be analyzed to determine the use of the resources it performs.