To sort a result, use an ORDER BY clause.
The most general way to satisfy a GROUP BY clause is to scan the whole table and create a new temporary table where all rows from each group are consecutive, and then use this temporary table to discover groups and apply aggregate functions (if any).
ORDER BY [col1],[col2],.[coln]; Tells DBMS according to what columns it should sort the result. If two rows will have the same value in col1 it will try to sort them according to col2 and so on.
GROUP BY [col1],[col2],.[coln]; Tells DBMS to group (aggregate) results with same value of column col1. You can use COUNT(col1), SUM(col1), AVG(col1) with it, if you want to count all items in group, sum all values or view average.

It is part of total comprehensive income but is generally excluded from net income. Prior to SFAS 130, these three items-foreign currency translation adjustments, minimum pension liability adjustments, and unrealized gains or losses on available-for-sale investments-were disclosed as separate components of stockholders' equity on the balance sheet. Under SFAS 130, they are to be reported as OCI. Furthermore, they must be reported separately, as FASB decided that information about each component is more important than information about the aggregate. Later, net unrealized losses on SFAS 133 derivatives were also included in the definition of OCI. The intent of SFAS 130 was that "if used with related disclosures and other information in financial statements, the information provided by reporting comprehensive income would assist investors, creditors, and other financial statement users in assessing an enterprise's economic activities and its timing and magnitude of future cash flows."

Aggregate tables are pre-computed totals in the form of hierarchical mutidimensional structure.,whereas materliazed view is the database object which caches the query result in a concrete table and updates it from the original database table from time to time .Aggregate tables are used to speed up the query computing whereas materialized view speed up the data retrieval .

Groupby -->  It is a way to sub-total your results,or perform some other 'aggregate' functions on them.
Orderby -->  It is a simply a way to sort your results. It doesn't affect what shows up in your result set,only 
                     what order it is displayed