The difference between Brother and Comrade

When used as nouns, brother means son of the same parents as another person, whereas comrade means a mate, companion, or associate.

When used as verbs, brother means to treat as a brother, whereas comrade means to associate with in a friendly way.

check bellow for the other definitions of Brother and Comrade

Brother as a noun:

Son of the same parents as another person.
Brother as a noun:

A male having at least one parent in common with another (see half-brother, stepbrother).
Brother as a noun:

A male fellow member of a religious community, church, trades union etc.

Examples:

"Thank you, brother."

"I would like to thank the brother who just spoke."
Brother as a noun (African American Vernacular English):

A black male.
Brother as a noun:

Somebody, usually male, connected by a common cause or situation.
Brother as a noun:

Someone who is a peer, whether male or female.

Comrade as a noun:

A mate, companion, or associate.
Comrade as a noun:

A companion in battle; fellow soldier.
Comrade as a noun (communism):

A fellow socialist, communist or other similarly politically aligned person.

Examples:

"Hello, comrade. Are you going to the Communist Party meeting tonight?"
Comrade as a noun (communism):

Examples:

"'Comrade Lenin inspired our people to undertake great works."