When something is given a 'boost', it improves in performance or outcome. You can 'boost sales', or 'boost the quality' of something - and, of course, you can 'Boost a Post' on Facebook. This action is designed to increase the reach of the post and improve its performance in terms of recognition. A person can be given a 'boost of confidence', or you can say that something 'boosted your confidence'. This means that it made you feel better about yourself and improved your outlook for the future.

1. The convincing win, after a run of heavy defeats, really helped to boost the morale of the team and gave them a lot of confidence going into their next match.

1. The company's ambitious and costly advertising campaign succeeded in boosting flagging sales of the product.
2. I wasn't expecting much when I first applied for the job, but I think that my performance in the interview has really boosted my chances of getting it.