In Russia, the double-headed eagle was always accompanied by another national symbol: a horseman slaying a serpent with a spear, portrayed on a shield. The horseman is a symbol of Russia’s capital, Moscow, and usually represents St. George the Victorious. However, since Russia is a secular state, this interpretation is unofficial.
The coat of arms has changed throughout history, with the eagle changing from gold to black, and then back to its current gold. Also, it has gained and lost the crowns over its heads. Currently, each head is topped with another crown ‘floating’ between them, which once more symbolizes unity. In its talons, the eagle holds an orb and a scepter – symbols of power and authority.
The current interpretation of the coat of arms is quite similar to those used in the Russian Empire. After the monarchy was overthrown in 1917, the eagle became white (maybe it just turned pale). With the Bolsheviks in power, the bird had a rest for about 70 years, and was replaced by the hammer and sickle. Since 1993 the eagle is back, still looking in opposite directions, and wearing three crowns on two heads.
https://www.rbth.com/history/327634-why-is-double-headed-eagle-a-symbol-of-russia