"Sr" is an abbreviation for "senior," often used to distinguish an older person from a younger counterpart with the same name. For example, in families, a father might be referred to as John Smith Sr. if his son is named John Smith Jr.. This designation helps clarify relationships and lineage. In professional settings, "Sr" can indicate a higher level of experience or responsibility. For instance, a Senior Manager typically has more experience and oversees larger projects than a Manager. This title helps organizations identify roles and hierarchies within their workforce.