What are pixel dimensions?

Pixel Dimensions are the number of pixels wide and the number of pixels tall of a sensor. They are multiplied to find the total number of pixels on a sensor. Here is an illustration showing how pixel dimensions of a Canon 7D would be determined.

Property of Dpi resolution (dots per inch)

Dots per inch (DPI) is a measure of spatial printing or video dot density, in particular the number of individual dots that can be placed in a line within the span of 1 inch (2.54 cm).

 Image quality is a characteristic of an image that measures the perceived image degradation (typically, compared to an ideal or perfect image). Imaging systems may introduce some amounts of distortion or artifacts in the signal, so the quality assessment is an important problem.

Compression setting are when you decide how big or small the photograph is going to be.

A raster image is made of up pixels, each a different color, arranged to display an image.

A vector image is made up of paths, each with a mathematical formula (vector) that tells the path how it is shaped and what color it is bordered with or filled by.
 
The major difference is that raster image pixels do not retain their appearance as size increases – when you blow a photograph up, it becomes blurry for this reason. vector images do retain appearance regardless of size, since the mathematical formulas dictate how the image is rendered.

File types

•  .tiff stands for Tagged Image File Format; a format for various imaging applications, including those that scan and fax. 
•  .jepg stands for 'Joint Photographic Experts Group'. It is a format for image compression which involves the glossy compressing for photographic images.
•  .png stands for Portable Network Graphics. It is a format for encoding a picture pixel by pixel for the purpose of sending it over the World Wide Web. 
• .bmp is a graphics file format for Microsoft windows bitmap. This format maps an image pixel, bit by bit. It is the only graphics format where compression actually enlarges the file. 
• .gif refers to an abbreviation which has different definitions depending on the context used. For instance, it could be used to refer to Graphics Interchange Format, Graphic Image File, Group Interchange Format or Giant Interchange Format. 
• .pdf is a type of document format, which means ‘Portable Document Format’. It is a widely used format on the Internet. To view a PDF document, you need a PDF reader or viewer application.