logo is a graphical element, symbol, or icon that, together with its logotype (which is set in a unique typeface or arranged in a particular way) form a trademarkor brand. A typical logo is designed to cause immediate recognition by the viewer. The logo is one aspect of the brand of a company or economic entity, and the shapes, colors, fonts and images are usually different from others in a similar market. Logos may also be used to identify organizations or other entities in non-economic contexts.
The noun symbol has 2 senses First 2 from tagged texts (18) SYMBOL -- (an arbitrary sign (written or printed) that has acquired a conventional significance) (2) symbol, symbolization, symbolisation, symbolic representation -- (something visible that by association or convention represents something else that is invisible; "the eagle is a symbol of the United States")
PICTOGRAM Another things that characterises Pictogram symbols is their stylistic design, using only those details that are most important and that provide the most information. In this way, the user's thoughts are led in the right direction. Generalisation of the symbols builds on the most characteristic concepts of reality that the respective symbols are supposed to depict.Excluding colours from Pictograms both increases the contrast to the eye and increases the generalisation of the symbols. Colours are only used in the Pictogram symbols for the seven days of the week.Such concepts as love, however, cannot be depicted by anything concrete in the material world around us. For this reason, the Pictogram system includes ideograms that are built upon something similar to the concept. A heart, for example, symbolises the noun "love", and a heart with an arrow going through it pictures the verb "to love". The symbols fill their function first when the user, with some background kowledge, can make the connection between love and heart.Because the combination of white on black provides the optimal contrast, pictograms are always white and black, expect for thesymbols for the days of the week. This picture shows how the pictogram symbols can be used for planning calendars that remind users when to go to school, to shop, etc.