Answer:
A Closeable is a source or destination of data that can be closed. The close method is invoked to release resources that the object is holding (such as open files).
Explanation:
hope it help?
The answer is SMTP (Simple Mail Transfer Protocol)
SMTP is a TCP/IP protocol used in sending and receiving emails. This service is usually used with two other protocols, IMAP or POP3. Most email systems nowadays used SMTP to send messages from one server to another. Generally, an SMTP is used to send messages from a mail client to a mail server.
Answer:
Primary key retains its uniqueness even after you remove some of the fields.
Explanation:
I am assuming that this question is related to database. Therefore, I am answering it according to database context.
In database, you can have multiple rows and columns. Each column shows a specific attribute while each row plots the data according to the attributes. However, there is the first column of each of main table that has unique set of values. It is called the Primary Key. Some key features of primary key are:
- It always contains the unique value.
- Its value cannot be null.
- A table can have at max one primary key.
- It can be the combination of multiple columns but it must be unique.
Therefore, the primary key has the ability to retain its uniqueness even after you remove some of the fields.
