What is a common mode choke, can bus common mode choke

ACM Series 2824 15 mOhm 4 A 15 mOhm DCR 50 V SMT Common Mode Filter Website URL: https://www.futureelectronics.com/p/passives–filters–common-mode-chokes/acm7060-701-2pl-tl01-tdk-8292815 Country List: Bangladesh