The question "How many characters does this question contain" contains 44 characters, including spaces and punctuation.
26
An email address can contain digits, but there is no specific limit to the number of digits it can have. The total length of an email address, including letters, digits, and special characters, cannot exceed 254 characters. Each part of the email (local part and domain) can vary in length, and digits can appear anywhere within those parts.
There are 16 bits in a port address, which gives a port range of 0 - 65535
As many as you like.
25
A MAC address consists of 12 hexadecimal characters, representing 6 bytes in total. The first 6 characters of a MAC address represent the Organizationally Unique Identifier (OUI) and correspond to 3 bytes. Therefore, the first 6 characters of a MAC address occupy 3 bytes.
You can change password as many times you want. The password must be minimum 8 characters of length. It must contain numerals and characters too.
The entire folder path can not contain more than 255 characters.
There are 8 characters which filename can obtain
seven, three for common hardware and four with m1 peculiar items
It depends on which database server, or software, you're referring to.