SpatiaLite is a spatial extension to SQLite

SQLite

SQLite is an ACID-compliant embedded relational database management system contained in a relatively small C programming library. The source code for SQLite is in the public domain and implements most of the SQL standard...

, providing vector

Vector graphics

Vector graphics is the use of geometrical primitives such as points, lines, curves, and shapes or polygon, which are all based on mathematical expressions, to represent images in computer graphics...

 geodatabase

Geodatabase

A geodatabase is a spatial database designed to store, query, and manipulate geographic information and spatial data of low dimensionality. It is a specialized type of spatial database often with optimizations for 2 and 3 dimensions, raster data and Euclidean distance.Within a spatial database,...

 functionality. It is similar to PostGIS

PostGIS

PostGIS is an open source software program that adds support for geographic objects to the PostgreSQL object-relational database. PostGIS follows the Simple Features for SQL specification from the Open Geospatial Consortium .-Features:...

, Oracle Spatial

Oracle Spatial

Oracle Spatial forms a separately-licensed option component of the Oracle Database. Oracle Spatial aids users in managing geographic and location-data in a native type within an Oracle database, potentially supporting a wide range of applications — from automated mapping/facilities-management and...

, and SQL Server

SQL Server

SQL Server may refer to:* Any database server that implements the Structured Query Language* Microsoft SQL Server, a relational database server from Microsoft* Sybase SQL Server, a relational database server developed by Sybase...

 with spatial extensions, although SQLite

SQLite

SQLite is an ACID-compliant embedded relational database management system contained in a relatively small C programming library. The source code for SQLite is in the public domain and implements most of the SQL standard...

/SpatiaLite aren't based on client-server architecture: they adopt a simpler personal architecture. i.e. the whole SQL engine is directly embedded within the application itself: a complete database simply is an ordinary file which can be freely copied (or even deleted) and transferred from one computer/OS to a different one without any special precaution.