The sale of assets is a form of acquisition .
A Inc. can just decide to acquire substantially all of the assets of B Inc. A Inc. has the assets of B Inc. and B Inc has the consideration paid for the assets (stock, cahs or other securities). Thereafter, there are two options. B Inc. may remain in existence as a holdign company, keeping the consideration and its sharehodler. Another possibilty is that B Inc. is liquidated with teh consideration received from A Inc. distributed to B Inc. shareholders in liquidation.
State law usually provides that, in a sale of assets, the boards of both corporations must approve of the sale. In general, only the shareholders of B Inc. have the right to vote on the sale when the sale involves all or substantially all of B Inc's assets.