I am quite new to working with JavaScript as well as geo location systems. I am looking for an open source JavaScript library to show - on the web - something very like the running trackers show you - (route)
But with a slight twist. It is a citizen science project in early stages, and I wish to be able to show the ployline, colored (something like a heat-map, traffic congestion) based on a variable.
The data is gathered and pushed into a csv/json file - I am open to the format of file. It contains information like time, latitude, longitude, variable1, variable2 and so on.
The idea is that polyline is based on the latitude and longitude info and the color gradients are based on the variables.

I do not know yet how to integrate time into it too...but that is a question for another time.

I am quite frankly overwhelmed by the information and libraries and APIs I have found because I don't have a clue about the general terminologies (tiles, vector tiles, overlays, layers, tracking, routing, polyline) too when it comes to designing web applications like this.

I found the following libraries/apis -

I am not really interested in using Google Maps APIs. I want an open source and a relatively simple library.

JavaScript is a must as its a web application and i wish to make an automated system that dynamically updates when information is added to the data file.

I quite frankly don't know what is the need of subscribing to various APIs and getting their keys. Since I am already getting the lat and log info, I thought I could just include js libraries that plot that easily given the lat and long.

If you could point me out to a few resources for beginners that would explain those terminologies and let me understand the nuances of designing geo position information systems, it'd be great since I'd like to solve things on my own but I don't know the ABC of GIS.