The Container class is the manager of the entire tsParticles instance. If you get the result of Engine.load | tsParticles.load the result it's this class, in the Engine.loadJSON | tsParticles.loadJSON is the then parameter.
Otherwise you can retrieve any loaded instance using Engine.items | tsParticles.items or Engine.item | tsParticles.item(index).
Container.id: the Container id, normally is the related DOM element Container.id attribute. It's set by Engine.load | tsParticles.load() and Engine.loadJSON | tsParticles.loadJSON().
Container.options: Where to find the current options loaded. Changing this options while playing can result in an unexpected behavior. A refresh | refresh() after the change is the best thing to do.
Container.sourceOptions: The options used when the Container was created, these options will be used only in the constructor.
Container.particles: The particles manager, you can add/remove particles from here.
Container.play | play(): Used to resume the animations, can be stopped using pause | pause().
Container.pause | pause(): Used to pause the animations, can be restarted using play | play().
Container.destroy | destroy(): Prepare the instance to destruction, you won't retrieve this instance anymore. Only if you have a variable set with it.
Container.exportImage | exportImage(callback, type?, quality?): Exports an image of the canvas (without the background property if set), type and quality are optional and are the image output type and quality.
Container.exportConfiguration | exportConfiguration(): Exports the current configuration in JSON, returns a string
Container.start | start(): Starts the container, it's different from play | play(), this will reload everything.
Container.stop | stop(): Stops the container, it's different from pause | pause(), this will clean up what need to be reloaded.
Container.refresh | refresh(): Restarts the container, just a stop | stop()/ start | start() shortcut.
Container.loadTheme | loadTheme(name): Sets the specified theme reloading options, if name is undefined the default theme will be used (if set)