This card is so rich with detail, good views of the trams, but also people going about their business, a coffee-roasting business, an auto-mat cafe, and a sign for Union Castle Mail Steamship Company.
Hamburg had a tram system from 1866 until 1978. Horse-drawn trams were in operation until 1922, running alongside steam-powered from 1878 until 1897 when electric-powered trams were introduced. There has been some discussion about re-introducing streetcars to Hamburg, but there are no plans right now.
Here's the back of the card.