Local temp tables are only available to the current connection for the
user; and they are automatically deleted when the user disconnects
from instances. Local temporary table name is stared with hash (“#”)
sign.

例：

CREATE TABLE #LocalTempTable(
UserID int,UserName varchar(50),UserAddress varchar(150))

本地临时表的范围仅与当前用户的当前连接相关.

全球临时表

Global Temporary tables name starts with a double hash (“##”). Once
this table has been created by a connection,like a permanent table it
is then available to any user by any connection. It can only be
deleted once all connections have been closed.

例：

CREATE TABLE ##NewGlobalTempTable(
UserID int,UserAddress varchar(150))

所有sql Server连接都可以看到全局临时表.当您创建其中之一时,所有用户都可以看到它.

Vignesh你可以更多地了解这个here