I noticed that some stocks could have two tickers (such as AGBA/AGBAU and LOAC/LOACU) and although the underlying company is the same, the prices for tickers with or without U are slightly different. I googled it but failed to understand what exactly U means.
Some sites, such as Investopedia, does say that the fifth letter "U" means units. But then what does "unit" mean here?