Kodama is the slowest of the trains services running on the Tokaido/Sanyo Shinkansen. It stops at every station along the route which it covers. Generally, you would not ride the Kodama if you wanted to go between major cities such as Tokyo and Osaka; take the Nozomi or the Hikari instead. The trains following Kodama routes are historically the slower and older ones, including the original 0 Series trains. Today 300 Series and 700 Series trains also operate as Kodama.
The word kodama (木霊 or 木魂) in Japanese means "echo".