What are the purposes of connecting condensers to tweeters?

Speaker is a cupper coil that vibrates and thus making sound. Music is a AC current that flows thru this coil. At low frequencis the resistance of a coil is low and this low resistance means high current that may damage speaker coil. The cendenser cut this low frequencis so only the high frequencis can drive the tweeter and make it safe. Overall at AC current lower the frequency lower the coil resistance and higher the condenser resistance. Higher the frequency higher the coil resistence and lower the condenser resistence.