* Bûches: This is the most common and general term for logs, often used for firewood.
* Troncs: This translates to "trunks" and can be used for larger logs or the trunk of a tree.
* Grumes: This term is used for logs intended for processing, like lumber.
* Bois de chauffage: This literally means "heating wood" and refers to logs specifically used for burning in a fireplace or stove.
The best translation for "logs" will depend on what you're referring to.