No, they are different. Per IEEE:
Switchgear: A general term covering switching and interrupting devices and their combination with associated control, instrumentation, metering, protective and regulating devices with associated interconnections, accessories and supporting structures used primarily in connection with the generation, transmission, distribution and conversion of electric power.
Switchboard: A large single panel, frame or assembly of panels, on which are mounted, on the face or back or both, switches, overcurrent and other protective devices, buses and usually instruments.
Switchgear and switchboard structures are built and tested to different standards: Switchgear to ANSI standard C37.20.1, UL standard 1558, and NEMA standard SG-5, switchboards to NEMA PB-2, and UL-891. Switchgear incorporates only low-voltage power circuit breakers (LVPCB) which conform with ANSI C37.13, NEMA SG-3 and are listed per UL-1066, whereas switchboards may include any combination of protective devices including insulated case (ICCB), molded-case circuit breakers (MCCB) listed per UL-489, fusible switches listed per UL-508 and 977 and power circuit breakers listed to UL-1066.
Best way to know the difference, Switchgear is designed for flexibility and maximum protection, switchgear generally costs 2x what switchboards do. Switchboards are designed to be low cost, usually use cheap MCCB's or ICCB's, and have very few features.