The hardware and software functions of a GIS are
(i) Data input and verification
(ii) Compilation
(iii) Storage
(iv) Updating and changing
(v) Management and exchange
(vi) Manipulation
(vii) Retrieval and presentation
(viii) Analysis and combination

The advantages of GIS are
(i) Maps produced by GIS analysis can be used to pinpoint problem areas.
(ii) GIS finds its strongest use in resources management, telecommunications and urban and regional planning.
(iii) GIS helps in planning the land-use requirements. The local government uses GIS for taxation and planning.

(i) Remote sensing can be either passive or active.
(ii) Active systems emit their own source of light energy such as RADAR:
(iii) Passive systems depend on sunlight as energy source

(i) Point Symbols - Buildings, dipping tanks, trigonometrical beacons
(ii) Line Symbols - Railways, roads, power lines, telephone lines
(iii) Area Symbols - Cultivated lands, ponds, orchards and vineyards

A cartographer is one who measures, analyzes and interprets geographical information to create maps and charts for political, cultural and educational purposes.

(i) In the 2151 century, GNSS has become a part of our lives to promote the safety and convenience of transport.
(ii) Global Navigation Satellite System (GNSS) is a satellite system connected with a small electronic receiver or tracker to locate, monitor and track a user's vehicle wherever in the world.
(iii) It can also set up instant alerts when a driver of a vehicle speeds or deviates from a particular area.
(iv) GNSS applications are used in tracking or mapping vehicles, ships and aircraft.
(v) A group of satellites (Space Segment) working with a network of ground stations (Control Segment) provide location data.
(vi) The receiver (User Segment) converts satellite signals into location, speed and time data.
(vii) Examples of GNSS:
(a) Europe's Galileo
(b) USA's NAVSTAR Global Positioning System (GPS)
(c) Russia's Global'naya Navigatsionnaya Sputnikovaya Sistema (GLONASS)
(d) China's BeiDou Navigation Satellite System
(e) India's NAVIC satellite system

(a) Advantages of Remote sensing:
(i) It is the only practical way to obtain data from inaccessible regions, e.g. Antarctica, Amazon forest.
(ii) It helps in constructing cheap base maps in the absence of detailed land surveys.
(iii) It detects the spread of natural calamities such as flood, forest fire and volcanic eruption, so that immediate rescue operations and planning can be carried out.
(b) Disadvantages of Remote sensing:
(i) It is difficult to prepare large scale maps from obtained satellite data.
(ii) The technique is very expensive for small areas requiring one time analysis.

(a) On the basis of scale, maps can be classified into:
(i) Large scale maps: Large amount of detail; can only show a small area.
(ii) Small scale map: Small amount of detail; can show a large area.
b) On the basis of utility and purpose, they are classified as:
(i) General maps / Topographic Maps (physical and political maps)
(ii) Thematic map (spatial variations of single phenomena)
(iii) Special purpose maps (Braille maps for blind people, maps for neo literates, military maps, navigational charts, etc).