This paper presents a study of star formation rates (SFRs) in 50,000 optically-selected galaxies in the local universe (z ≈ 0.1), spanning from gas-rich dwarfs to massive ellipticals. The SFRs are derived using GALEX (ultraviolet) and SDSS (optical) photometry, combined with population synthesis models that include dust attenuation. The UV-based SFRs are compared with those derived from SDSS emission lines (primarily Hα), showing good agreement, except for systematic deviations due to differences in dust attenuation estimates. UV provides reliable SFRs for galaxies with weak or no Hα emission, and where Hα is contaminated by AGN emission. A simple prescription is calibrated using full SED SFRs, GALEX far-UV magnitude, and UV slope to produce dust-corrected SFRs for normal star-forming galaxies. The specific SFR is considered as a function of stellar mass for three groups: (1) star-forming galaxies without AGN, (2) those hosting an AGN, and (3) galaxies without Hα emission. The three groups have distinct star formation histories, with AGN lying intermediate between star-forming and quiescent galaxies. Normal star-forming galaxies lie on a narrow linear sequence, while galaxies hosting strong AGN appear to represent the massive continuation of this sequence. Weak AGN, while also massive, have lower SFRs, sometimes extending to quiescent galaxies. The study proposes an evolutionary sequence connecting normal star-forming galaxies to quiescent galaxies via strong and weak AGN. It confirms that some galaxies with no Hα emission show signs of star formation in the UV. A UV-based cosmic star formation density at z=0.1 is derived with significantly smaller total error than previous measurements. The study uses GALEX and SDSS data to obtain a large sample of galaxies with both UV and optical photometry, as well as spectroscopic redshifts. Dust-corrected SFRs and other physical properties are obtained by comparing observed colors to stellar population synthesis models with dust attenuation. The study compares UV-based SFRs with those derived from SDSS spectra for ~10^5 galaxies. It discusses star formation histories of different galaxy classes and derives a UV-based estimate of the global star formation density at z=0.1. The study also explores the effects of dust attenuation on UV and Hα SFRs, and the differences between various SF indicators. The study finds that UV-based SFRs are more reliable for galaxies with weak or no Hα emission, and where Hα is contaminated by AGN. The study also finds that the UV-to-optical color-magnitude diagram shows a pronounced bimodality of blue and red galaxies, with the blue sequence representing star-forming galaxies and the red sequence representing quiescent galaxies. The study concludes thatThis paper presents a study of star formation rates (SFRs) in 50,000 optically-selected galaxies in the local universe (z ≈ 0.1), spanning from gas-rich dwarfs to massive ellipticals. The SFRs are derived using GALEX (ultraviolet) and SDSS (optical) photometry, combined with population synthesis models that include dust attenuation. The UV-based SFRs are compared with those derived from SDSS emission lines (primarily Hα), showing good agreement, except for systematic deviations due to differences in dust attenuation estimates. UV provides reliable SFRs for galaxies with weak or no Hα emission, and where Hα is contaminated by AGN emission. A simple prescription is calibrated using full SED SFRs, GALEX far-UV magnitude, and UV slope to produce dust-corrected SFRs for normal star-forming galaxies. The specific SFR is considered as a function of stellar mass for three groups: (1) star-forming galaxies without AGN, (2) those hosting an AGN, and (3) galaxies without Hα emission. The three groups have distinct star formation histories, with AGN lying intermediate between star-forming and quiescent galaxies. Normal star-forming galaxies lie on a narrow linear sequence, while galaxies hosting strong AGN appear to represent the massive continuation of this sequence. Weak AGN, while also massive, have lower SFRs, sometimes extending to quiescent galaxies. The study proposes an evolutionary sequence connecting normal star-forming galaxies to quiescent galaxies via strong and weak AGN. It confirms that some galaxies with no Hα emission show signs of star formation in the UV. A UV-based cosmic star formation density at z=0.1 is derived with significantly smaller total error than previous measurements. The study uses GALEX and SDSS data to obtain a large sample of galaxies with both UV and optical photometry, as well as spectroscopic redshifts. Dust-corrected SFRs and other physical properties are obtained by comparing observed colors to stellar population synthesis models with dust attenuation. The study compares UV-based SFRs with those derived from SDSS spectra for ~10^5 galaxies. It discusses star formation histories of different galaxy classes and derives a UV-based estimate of the global star formation density at z=0.1. The study also explores the effects of dust attenuation on UV and Hα SFRs, and the differences between various SF indicators. The study finds that UV-based SFRs are more reliable for galaxies with weak or no Hα emission, and where Hα is contaminated by AGN. The study also finds that the UV-to-optical color-magnitude diagram shows a pronounced bimodality of blue and red galaxies, with the blue sequence representing star-forming galaxies and the red sequence representing quiescent galaxies. The study concludes that