Lawrence Garvin is correct.
The Directory Service Query Tool (with the orange wrench) is how you configure the LEM to reach out to LDAP and pull in information about users (so you can log in with domain credentials) and groups. It's also how the LEM will perform response actions on AD if your rules call for it, like unlocking or disabling accounts.
SolarWinds Knowledge Base :: How to create LEM console users with domain credentials
The Directory Service Log Connector (the blue wrench) is a reader: it looks for Directory Service logs, and normalizes them for the alert database.
As a note, we use that color code with all connectors: blue connectors are usually passive, gathering data and normalizing it for the LEM. Orange connectors are there to perform some sort of action, which is why the Email Active Response connector is Orange, but the Exchange log connectors are blue.