The blue pale symbolizes Turkic heritage, the red color is for the progress to establish a modern state and the development of democracy, the green strip shows the nation's relation to the Islamic civilization. In the middle of the red strip on both sides of the flag there is a white-color crescent and an eight-point star. The first President of the Mammed Amin Rasulzade also noted in his speech, at the parliament's session of Azerbaijan Democratic Republic, that the meaning of the colors relate to Turkic freedom, modernity and Islamic culture. The composer of the anthem of Azerbaijan Uzeyir Hajibeyov wrote on the flag meaning: blue color – the color of Turkism, red – the color of progress and culture, and green – the color of Islam.
The views of historians and researchers differ on the meaning of the crescent and star on the flag. According to historian Nasib Nasibli, Alibay Huseynzadeh, one of the ideologues of Azerbaijan’s independence, developed the combination based on colors used in 1895. The crescent on the flag symbolizes Islam, and the eight-pointed star on the flag symbolizes Fatali Khan Khoyski points to the eight letters in the name "Azerbaijan" (written in Arabic script). Some researchers have noted that under Kipchaks at the time it referred to the Kazakhs and Kyrgyz. Also the classification of Turkic peoples in the early 20th century was different from the current.source: wikipedia