1) The first commercially available digital camera, the Dycam Model 1, was introduced in 1990 and had a resolution of 376 x 240 pixels.

2) The European Union (EU) is a supranational organization comprising 27 member states that cooperate on various issues, including trade, economic integration, and common policies, while preserving individual national sovereignty.

3) In Norse mythology, the World Tree, known as Yggdrasil, is a massive ash tree that connects the nine realms of existence. It is considered the center of the cosmos and serves as a conduit between different realms, including Asgard (realm of the gods), Midgard (realm of humans), and Helheim (realm of the dead).

4) The term "bull market" refers to a period of rising stock prices, while a "bear market" refers to a period of falling stock prices.