Old Roblox is typically referred to as the 2006 - 2012 era of Roblox. Players from that time see it as a "nostalgic heaven" whereas anyone with at-least one braincell will remember it was a toxicity haven. No filter besides super safe chat, clunky physics and that crispy anti-aliasing that didn't exist.
People from this era might chant "bring back tix" (roblox lingo for a ticket currency) or cry about the forums being removed.
the person who wrote the other definition is underage
web.roblox.com sends you to roblox.com if you're not logged in or if your account is 13+
web.roblox.com is roblox but for <13 accounts