伙伴本作火伴，约定俗成为伙伴或伙伴，指一同生活或者共事者，源起于军人同火之意思。此词亦引申解作工作搭档或商业之间的合作关系。

此称呼仍然流行于香港纪律部队，俗称「火记」。

中国古代军队每十名士兵共用一火煮食，同火者互称火伴；因偏旁类化作伙伴，沿用至今。而中国大陆将伙简化归并为伙，使很多人以为伙伴才是正写。

相关词汇还有「火拼」，原解作内哄，即一「火」的人互斗。

火记乃差人（警察）用以互相称呼，是火伴的意思，亦即一同出生入死的火伴。伙和伙字均为误写，正写实为火字。另外，广东人同时习惯以记字代替商号或名字全称。例如已故香港歌手罗文，人称罗记；麦当劳餐厅，人称麦记，就是例子了。

A Battle Buddy is a partner assigned to a soldier in the United States Army. Each Battle Buddy is expected to assist his or her partner both in and out of combat. Most participating soldiers have reported satisfaction and have agreed that the Army should implement the system fully, although there have been cons reported as well. A Battle Buddy is not only intended for company, but also for the reduction of suicide; since each watches his partner's actions, a Battle Buddy can save their fellow soldier's life by noticing negative thoughts and feelings and intervening to provide help.