The "Direct Message" between people is the easiest to understand and is just like a standard chat service. This is chatting directly on anything without nominating any specific topic.
Chat to a person (1:1)
Chat to a group of people (1:M)
3. Topic Message
Besides arranging your messages based on who you chat to (as in Direct Message above), you can also arrange messages based on topics. You can arrange topics based on people involved (Teams).
Teams - define people with access to topic
Channels - define topics within that group of people
4. Hierarchical Structure
Both Direct and Topic Messages can be arranged in a hierarchical manner:
Discussions - breaking topic down into smaller sub-topics
Threads - breaking sub-topics down into even smaller topics
5. Rockchat Search
In most cases just typing whatever you want to search in the search box will be enough.
But for more complex searching you need to type in Regular Expression syntax.
You can just type in the search string directly, but if you format your search with regex it will be more accurate.
For example:
Find a case sensitive word ABC
/ABC/
Find case insensitive word ABC
/ABC/i
Find case insensitive word ABC at the beginning
/^ABC/i
Find case insensitive word ABC at the end
/ABC$/i
Find whole word aaaaa with spaces on both sides
/\s+aaaaa\s+/i
Find text string bbbbb inside any word or by itself
/.*bbbbb.*/
Find either of ccccc OR ddddd.
/(ccccc|ddddd)/i
Find either of two whole words (with spaces on both sides) EITHER ccccc OR ddddd.
/( ccccc | ddddd )/
Find two text strings eeeee and fffff both occurring TOGETHER appearing in any order inside any word or by themselves
/(?=.*eeeee)(?=.*fffff)/i
Find two text strings both occurring TOGETHER with ggggg BEFORE hhhhh inside any word or by themselves