BASIC programmable calculator
These calculators are programmable in BASIC and sometimes also in C, Assembler or other. Calculations can often be entered as BASIC expressions and many calculators of this type have a mode in which they are entered algebraically.
These are the basic household calculators.
Calculator (unknown type)
For these calculators I have not been able to determine a proper type.
Desktop calculators are not covered on this site.
Financial programmable calculator
These calculators have functions targeting the financial market. They are also revered to as business calculators.
These calculators have functions for aviation and navigation. Most of them are not programmable.
Graphing calculators have functions for displaying mathematical problems in a graphical manner.
Organisers, or PDA (Personal Digital Assistants) are mainly used to store data like addresses and appointments. Some have quite advanced calculator functions, most however have only modest skills in this department.
These are not calculators, but printers...
Scientific programmable calculator
These calculators have functions targeted at scientists. They are often used for educational purposes.