Although the two names may sound similar but there is a huge difference between two. Both are social blockchain-based content creation platform with a native token called hive and uhive.
Hive came about as a result of the acquisition of Steem by Tron while uhive is a metaverse company based in the United Kingdom. On the hive platform you are rewarded based on your hive power which you can actually purchase and can be use to upvote contents to get more reward. But on Uhive you can be rewarded base on the amount of time you spend on the community, voting, commenting or checking out contents. You need your private key to log into your hive account, while you need a password or google account to log into your uhive account.
Uhive rewards are credited to wallet every 24 hours, while Hive rewards are credited to wallet every 7 days. On hive you can instantly withdraw your hive dollars, but on uhive it may take up to weeks to process your withdrawal. Hive withdrawal fees is minimal compared to uhive which uses ethereum network and the fees is on the high side.
As of the time of writing this Hive token price was at $1.11, while Uhive price was at $0.001975.