What is the purpose of the property, transition-timing-function? It sets how many times a transition will play.
It delays the start of a transition by a set number of seconds.
It changes the speed at different stages of the transition.
It adds a pause between steps in an animation.

It changes the speed at different stages of the transition.

Explanation:

HTML is an acronym for hypertext markup language and it is a standard programming language which is used for designing, developing and creating web pages.

Generally, all HTML documents are divided into two (2) main parts; body and head. The head contains information such as version of HTML, title of a page, metadata, link to custom favicons and CSS etc. The body of the HTML document contains the contents or informations that a web page displays.

Basically, the purpose of the property, transition-timing-function is that It changes the speed at different stages of the transition. Thus, it states the values between the beginning and ending of a transition are calculated over its duration.

the major difference between the two is the objective and the reward of the game. candy crush has a puzzle theme with the objective of meeting a specific quota of points or objects, you are able to gain access to the next level and compete with peers on the process. on duolingo the objective is rather different, you are given sets of questions for you to answer for you to move to the next level and as for the reward, you are able to learn available language as this is an app developed to teach the user about other languages.