Location based services (LBS) describes a service or application that extends spatial information processing to users over the internet. LBS  can be used to answer questions like: "Where is the closest diner?" or "How can I get home?". LBS involve location sensing technologies like e.g. GIS and GPS and the different technologies vary in cost, coverage and accuracy. LBS are often used on mobile devices, which requires a suitable generalization and visualization that is also appealing to casual users. The changing of location can be a challenging aspect within LBS when it comes to e.g. visualizing and certainty of geographic information (Jiang & Yao 2006).

Location-based Big Data (LocBigData) can be obtained by LBS. Some data is for instance automatically generated as a by-product when people use different services, like smart cards when travelling by public transportation. LocBigData can shed light on human mobility, city structure and dynamics. Research within the field can provide solutions to various urban issues. Data quality will have to be considered when using LocBigData, since its source include some challenges research-wise (Huang et al. 2021).

Web 2.0 generated a shift within GIS and spatial information services, and amongst countless other things, it made Volunteered Geographical Information (VGI) possible. In VGI, casual users can create content that is assorted with spatial coordinates. Examples of VGI are geotagged posts on social media and user-defined traffic reports. 

VGI-data can be analyzed, but the data has some limitations research-wise. For example, the data can come from many different sources and is not created by experts. The usage of VGI also varies within a popluation, which for example can exclude parts of the poor or the elderly generation. 

OSM is another example of a VGI. Steve Coast founded OpenStreetMap (OSM) in 2004 and today it has more than 10 000 000 users worldwide. 

Cartograms are maps where geometry is distorted in order to convey a certain attribute in the data, while retaining the topology. A famous example in this topic is the London tube map, created by the engineer Harry Beck in 1931, which set the framework for tube maps all over the world. 

There are numerous types of cartograms, for example area cartograms, non-contiguous cartograms and dorling cartograms. 

An area cartogram showing worldwide twitter activity in a 2-hour span.