All of the 501(c) sections, including 501(c)(3), describe particular types of organizations that qualify for tax exemption. Section 170 provides that contributions to certain types of organizations—primarily 501(c)(3)s and a few others—are deductible by the donor as itemized deductions. Section 501(c)(3) governs tax exemption of organizations, while section 170 governs deductibility of contributions by individuals.
DISCLAIMER: This information is not intended to provide legal or accounting advice, or to address specific situations. Please consult with your legal or tax advisor to supplement and verify what you learn here.