Training shield

The Training shield can be obtained for free from the melee combat tutor east of Lumbridge Castle. The shield has the appearance of a white decorative shield and has the same bonuses as a wooden shield. Players can ask the tutor for another shield if they lose the one they had, though players are only allowed one shield at any time.

Controversy
When the shield first came out, it looked exactly like the white decorative shield. Players that had spent a large amount of time playing Castle Wars to purchase the white decorative shield disliked the fact someone could walk around with the training shield and say they had a white decorative shield. Jagex changed the training shield's look by removing the blue line going across the shield, causing it to appear slightly different than the decorative shield.

The shield has became a stereotypical feature of low-leveled players along with the training sword. and usually those who wield it has fair chance of being called a noob by high-leveled players.

Tips
For new characters it is recommended to immediately sell your wooden shield and bronze sword to the Lumbridge general store then get a training sword and shield as you will make a minimal profit and lose nothing in armour quality,as the bronze sword and wooden shield have the same bonuses as the training equipment. Certain low-level mages use the training shield in combat as it adds a small amount of magical defense, unlike many other shields, which greatly decrease magic defense. Though many characters decide not to, as it doesn't look very aesthetically pleasing.

From RuneScape Wiki, a Wikia wiki.