Algeria is home to around 45 million people, making it the most populous country in the Maghreb. The population is overwhelmingly young -- more than half are under 30.
Most Algerians are Arab-Berber, but the distinction between Arab and Berber identity remains culturally significant. The Kabyle people of the mountainous Kabylie region east of Algiers are the largest Berber group, fiercely proud of their language and traditions. The Tuareg of the deep south around Tamanrasset and Djanet are another distinct group, with their own language, script, and nomadic heritage. The M'zab valley around Ghardaia is home to the Mozabites, an Ibadi Muslim community that has maintained its own social structures for centuries.
Arabic and Tamazight (Berber) are both official languages. French is widely spoken, especially in business, education, and daily life in the cities -- Algeria's 132 years as a French colony left deep linguistic roots. In the south, Tuareg languages are common. English is growing but still uncommon outside universities and the oil industry.
Algerians are famously hospitable. If you spend any time with local people, you will be offered tea, coffee, and food repeatedly. Refusing too firmly can cause offense -- at least accept a glass of tea. Conversations tend to be warm and direct. People will ask you personal questions and expect the same in return.
Islam shapes daily life. Algeria is almost entirely Sunni Muslim. During Ramadan, most restaurants close during the day, and eating or drinking in public before sunset is considered disrespectful. Alcohol is available but not widespread -- you will find it in some hotels and licensed shops, but Algeria is not a drinking culture. Dress modestly, especially outside the big cities.