Syria's conflict is mired in stalemate, with President Bashar al-Assad's forces defending Damascus and territory in the west and centre while rebels control the north and east, with neither able to make major advances.
DAMASCUS AND PROVINCE
After a failed attempt in summer 2012 to break into the heavily fortified capital, insurgents are confined to its southern and eastern edges, although senior regime officials have been targeted in multiple bombings.
The Eastern Ghouta region is home to well-organised rebel groups and has seen some of the country's longest-running battles.
Southwest of Damascus, the army aims to crush rebel Daraya, sending in daily reinforcements.
Few radical groups are active in the province, and rebels say that despite talk of a "final battle" for Damascus, the impasse is unlikely to change without a breakthrough on international arms backing for the opposition.
THE NORTH: IDLIB, ALEPPO, RAQA
Lined by the porous Turkish border, large swathes of Idlib province are controlled by insurgents, but the provincial capital is in army hands.
After hardline fighters took to the stage, among them a handful of battle-hardened foreign jihadists, rebels in Idlib took two border crossings to Turkey and the Taftanaz air base.
Overall, Islamists in the north have better access to weapons and rear bases than rebels farther inland.
Rebels in Aleppo control much of the countryside, and Syria's second city and former commercial hub itself became a battleground from July 2012.
With Islamist Liwa al-Tawhid brigade leading the fight for the city centre, the radical Ahrar al-Sham spearheads battles for the province's air bases.
Also active in Aleppo province is Al-Nusra Front, listed by the United States as a "terrorist" organisation.
In Raqa, Al-Nusra- and Ahrar al-Sham-led rebels made the most stunning insurgent advance yet when they captured the provincial capital on March 6, although regime warplanes still bombard rebel targets there.
As rebels seize more land, analysts say in-fighting may break out over ideology and turf.
THE EAST: DEIR EZZOR, HASAKEH
Smuggling in weapons and fighters across the border from Iraq, rebels have seized massive swathes of eastern Deir Ezzor province, although the army still controls much of the devastated provincial capital.
Rooted in Al-Qaeda in Iraq, Al-Nusra Front is strong in Deir Ezzor, as are rebels with cross-border tribal loyalties.
In Ras al-Ain in the Kurd-majority province of Hasakeh, rebels have battled both the army and Kurdish militia. Last month, negotiations brought a tense calm.
Elsewhere in Hasakeh, jihadists have seized large areas, sparking a mass exodus of the region's population.
THE CENTRE: HOMS, HAMA
After a nine-month siege on rebel districts and towns in Homs province, the army launched a new operation using pro-regime National Defence Forces fighters and warplanes aimed at crushing insurgent strongholds.
Reclaiming rebel enclaves in Homs would be an important symbolic victory for the regime, as would full control over central Syria, home to a sizable Alawite community.
Though insurgent groups stage hit-and-run operations across Hama province, the region is mostly under army control, as is the provincial capital despite a culture of dissent.
THE WEST: LATAKIA, TARTUS
The heartlands of the Alawite sect -- to which President Bashar al-Assad belongs -- are firmly under army control, barring enclaves in the Turkmen and Kurdish mountains north of Latakia.
THE SOUTH: DARAA, SWEIDA, QUNEITRA
In Sweida, where most of Syria's Druze community live, rebels have organised a Military Council. But community leaders have called for neutrality in the conflict, and the province is mostly peaceful.
On the sensitive ceasefire line with Israel, Quneitra province has seen occasional clashes between rebels and the army.
In Daraa, so-called cradle of the revolt, rebels have seized several villages, but most of the province remains in army hands.