Sanctions are official penalties for cause. For example, the United Nations may impose "sanctions" on a member nation, or an organization may impose "sanctions" one of its members for reflecting poorly on the organization.
At law, "sanctions" are penalties imposed by a judge on one of the parties to a suit, at the recommendation of opposing counsel. They can be used for abuses of discovery or other abuses of law at trial, such as contempt of court, or tardiness.
Depending on the issuing judge, the bar for sanctions may be high, or low. Some judges take them very seriously; others use them fairly at will. Like much in law, it depends on the judge.