In recent decades, fluorescence imaging has emerged as a pivotal technique in life science for the direct visualization of dynamic living processes. Given the crowded nature of biological environments, achieving high-resolution imaging with an ultrahigh signal-to-noise ratio is of utmost importance for accurately monitoring chemical events. Therefore, significant efforts have been devoted to developing practical methodologies to obtain bright and high-resolution images. These strategies span from innovations in microscope design and imaging system optimization to intricate molecular-level and nano-interface engineering of fluorescent probes.