The dictionary defines testing as : something (as a series of questions or exercises) for measuring the skill, knowledge, intelligence, capacities, or aptitudes of an individual or group.

While assessments is define as An evaluation or estimation of the nature, quality, or ability of someone or something

Testing in my opinion is a collective of skills and knowledge that is put in to questions or exercises. An example of this is the end of the semesters test it has reading, writing counting .Assessments is the ability to complete a certain task very specific like rolling a sushi.