Gladius was the Latin word for sword, and is used to represent the primary sword of Ancient Roman soldiers. Early ancient Roman swords were similar to those used by the Greeks.
The "spatha" was another, later type of Roman sword. At up to one meter in length, it was longer than a gladius, but had a similar, leaf-shaped or wasp-waisted design. Originally, the spatha was only worn by Roman cavalry officers, but it was eventually adopted for use by many Roman legionaries and their auxiliary troops. The spatha was a more advanced design for Roman swords, employing layers of iron and steel.
We have just about everything a Roman re-enactor could want. Historical Clothing Realm carries many types of Roman Swords that range from Roman Short Sword, Roman Gladius Sword, Roman Spatha sword and the Gladiator Sword.