老 before surnames shows familiarity and respect among peers: 老王, 老李. It's used for people of similar or older age — never for someone much younger than you.
culture
In Chinese culture, being 老 (old) is traditionally associated with wisdom and respect, unlike in some Western cultures. 尊老爱幼 (respect the old, love the young) is a core value.
Components
pictograph
老lǎo
old
Pictograph of an elder leaning on a cane: top 耂 portion shows long flowing hair and a stooped back, the bottom hooked stroke is the cane planted in the ground. 老 is itself a Kangxi radical (#125) heading the seniority family — 考 (examine), 者 (one who), 孝 (filial).
