Gremlin is a graph traversal language: think of Gremlin as the SQL for graph databases. Gremlin is not a graph database server, it is a language; but, there is a Gremlin Server and a Gremlin Console available for interacting with graph databases. It is possible to use Gremlin on large database platforms like Titan and HBase.
A graph database is based on graph theory. A graph is composed of nodes, edges, and properties. A key object/component in a graph database is stored as a node. Nodes are connected via edges representing relationships. For example, you may represent people as nodes and have edges representing friendships. You can assign properties to both nodes and edges. A person (node) may have the properties of age and name, where a friendship (edge) may have a start date property.
An IDE (Integrated Development Environment) is a single program that wraps everything you need to program with. An IDE usually consists of a code editor, debugger, and a compiler. A good IDE can make you more productive. Without a IDE you would be stuck writing all of your apps in notepad and compiling via command line – which is not bad for learning how to program. A good IDE has syntax highlighting which makes the code easier to read and error highlighting which makes finding that missing semi colon easier. Here is a list of three IDEs that work well for me.
When you get this error, it means that you are using the wrong version of JDK to run a specific java file. To fix this you must uninstall your current version of JDK. Next you must install the correct architecture of JDK. This for most people means install the 64-bit version of JDK.