The establishment of the Delhi sultanate marked a new phase in the cultural
development of the country. When the Turks came to India, they not only had
a well-defined faith in Islam to which they were deeply attached, they also
had definite ideas of government, arts, architecture, etc. The interaction of the
Turks with the Indians who had strong religious beliefs, well-defined ideas of
arts, architecture and literature resulted, in the long run, in a rich
development. But the process was a long one, with many ups and downs.
  Arch and Dome Method: The use of arch and the dome had a number of
  advantages. The dome provided a pleasing skyline. The arch and the dome
  dispensed with the need for a larger number of pillars to support the roof
  and enabled the construction of large halls with a clear view. Such places
  of assembly were useful in mosques as well as in palaces.
  Use of Superior Mortar: The arch and the dome needed a strong cement,
  otherwise the stones could not be held in place. The Turks used fine
  quality mortar in their buildings.
  Slab and Beam Method: The architectural device generally used by the
  Indians consisted of putting one stone over another, narrowing the gap till
  it could be covered by a caping stone or by putting a beam over a slab of
  stones which is known as the slab and beam method.
  Decoration: The Turks eschewed representation of human and animal
  figures in the buildings. Instead, they used geometrical and floral designs,
  combining them with panels of inscriptions containing verses from the
  Quran. Thus, the Arabic script itself became a work of art. The
  combination of these decorative devices was called arabesque. They also
  freely borrowed Hindu motifs such as the bell motif, lotus, etc. The skill of
  the Indian stone-cutters was fully used. They also added colour to their
  buildings by using red sand stone, yellow sand stone and marble.
Development and Growth
Ilbaris    They at first converted    temples and other existing buildings into