Explain Shockwave Flash?

Solution 1:

Originally, Macromedia made the Shockwave plugin for publishing Director content on the web. A smaller company called FutureWave developed an animation program called FutureSplash, also with a web plugin, which had a smaller resource footprint than Director (and might have had other advantages, I'm not sure). Macromedia, seeing this, bought FutureWave and renamed FutureSplash as Shockwave Flash, to serve as a companion to Shockwave. Eventually, Flash became the dominant technology. Later on, Adobe bought Macromedia.

Solution 2:

This name confusion arose earlier in the 90's when Macromedia players were prefixed with the word "Shockwave". After Adobe took over they rebranded all Shockwave products.

Source

Solution 3:

They had much the same origins back in the Macromedia days, but were intended for slightly different targets originally. Nowadays, it's mostly the same. See here