Accordance is a noun for matching a rule, a system, or an agreement — being in line with it, not fighting it. In the English students actually meet, the word almost never walks alone. It lives inside in accordance with: ‘in accordance with the law’, ‘in accordance with school rules’. That phrase is formal, the kind of English on notices, contracts, and official letters. Teachers and lawyers like it; friends almost never say it over dinner. Though actually there is a slightly older flavour of ‘agreement, harmony’ as well, but you will rarely hear that in the street. For everyday speech, people say according to, following, or just under the rules.