An embargo is a government restriction applied to the import or export of products, services, or currency from one country to another. You can read a detailed explanation of embargoes on Investopedia. You can also check current UK trade sanctions and embargoes on the GOV.UK sanctions list.
Embargoes can prohibit all trade or just a specific portion of it, such as the import of weapons. They are intended to punish the targeted country for its actions and deny it the ability to carry out objectionable policies. Businesses must use denied party screening and restricted goods screening to ensure they are not unknowingly trading with embargoed countries or entities.