They can be compared with errors, which are caused by a learner not knowing something. Some people use the term mistake to describe slips.
Example
A learner asked to speak in front of the group may make slips because she is nervous.
In the classroom
Creating a positive learning environment in the classroom can be done in many ways, including establishing a good rapport with and between learners, developing a real sense of autonomy and group decision-making, giving feedback on mistakes sensitively.
See also:
https://www.teachingenglish.org.uk/article/errors
https://www.teachingenglish.org.uk/article/mistakes
Further links:
https://www.teachingenglish.org.uk/article/error-correction
https://www.teachingenglish.org.uk/article/error-correction-1
https://www.teachingenglish.org.uk/blogs/george-chilton/george-chilton-we-all-make-mistakes
https://www.teachingenglish.org.uk/article/jordana-mazzarotto-ana-francisca-rosada-creating-a-positive-learning-environment