What is concept of terms, keywords and term sets?

Question

Keywords: Within a SharePoint 2013 site, descriptive metadata (words or phrases) can be directly assigned to any list item or document; these words and phrases are called keywords.

1. Are the keywords and enterprice keywords the same thing.

2. What are terms?

Although terms are stored within a series of term sets, enterprise keywords are stored within a single term set within the managed metadata service.

1. What are term sets? Can you give me a example so I can visualize this concept?

2. When do you convert a keyword to a term?

Answer 1

Terms are the basic unit or smallest item in Managed Metadata or Taxonomy. TermSet is just a collection of Terms.Like say if you want to create a taxonomy for countries and their cities. Country will become the TermSet (eg:England) and cities will be Terms inside respective termsets ie London will be term inside England.

Enterprise Keywords is a site column under Enterprise keywords group. It is a managed metadata column and is mapped to a pre defined Termset called Keywords. See this blog which explains Enterprise Keywords in detail.