Connectosrs joi youo elements on a diagram, and in some cases they indicate the order of precedence of these elements.
Flow elements refer to elements that are connected together to form a complete process flow. Connectors that connect the flow elements are called connecting objects. Readers of BPD follow the flow of elements to see how a business process gets executed and completed.
There are four kinds of flow elements: Activities (Task and Sub-Process), Events and Gateways, there are mainly two kinds of connecting objects: Sequence Flows and Message Flows.