There are two image formats: Vector and Bitmap.
Vector images are made up of many individuals, scalable objects. These are defined by mathematical equations rather than pixels, so they always render at the highest quality, even when enlarged. - They are typically used for images such as logos.
Bitmap images are made of individual pixels, each with a colour value. The bigger the picture, the more pixels are needed. If images are scaled up, quality is lost. - This format is used for photographs.
EPS = The Original (Vector = Scalable)
JPG = Website's and Social Media (Pixels = non-Scalable)
PNG = Transparent background (Pixels = non-Scalable)
AI: Adobe Illustrator
The AI file is the original, editable, working file.
EPS: Encapsulated PostScript
EPS format is a vector file that can be opened by the widest range of software, including older versions of Illustrator and products outside of Adobe.
SVG: Scalable Vector Graphics
SVG is a vector image format that can be used online. With higher resolution screens becoming more and more common since it’s a vector format, an SVG file will ensure the logo you designed remains sharp no matter the device it’s viewed on.
PDF: Portable Document Format
PDF format is becoming widely favoured by most designers as it can be universally viewed on any computer with Adobe Acrobat (or another PDF viewer). It’s also possible to preserve illustrator-editing capabilities when saving in this format, meaning it can be opened and modified in the same way an AI file can.
Raster files are made up of pixels. This means that as you increase the size of your image, it will become blocky or appear to be blurry. (A logo must be created in vector format).
Raster files are intended for computer use, so they are provided in RGB colour mode. RGB stands for Red, Green and Blue, which are the colours used to make up all the colours you see on your screen. Black is the absence of light. Raster file types have a file extension of .jpg or .png.
JPG/JPEG: (Joint Photographic Experts Group)
Jpeg’s are most commonly seen online. This is because jpeg offers excellent compression without overly degrading the image, meaning the file size is small and will load quickly.
PNG: (Portable Network Graphics)
A PNG is an image type commonly used in web design to provide a transparent background and/or a semi-transparent image. PNGs are often saved versions of logos as the image can be easily placed over a background of a picture, block of colour or pattern.
TIFF (Tagged Image File Format).
It is the most flexible and reliable method for strong bitmapped images in various resolutions, grey levels and colours. Tiff was created specifically storing greyscale data, and it is a standard format for scanned photographs. It can be compressed with its own LZW compression, non-lossy (no data is lost on expansion).
GIF (Graphic Interchange Format).
Is CompuServe's standard for compressed web graphics. It is a bitmap format that allows transparency but a limited range of colours.