Difference between 'pilot study' and 'pretesting' in research methodology

Most of the times these terms are used interchangeably. The International Development Research Centre Canada site mentions this difference between them:

A PRE-TEST usually refers to a small-scale trial of particular research components.

A PILOT STUDY is the process of carrying out a preliminary study, going through the entire research procedure with a small sample.

Link: http://www.idrc.ca/en/ev-56623-201-1-DO_TOPIC.html