A password in a one factor or multi-factor authentication is a mechanism not of what an entity has but what they know.
One factor authentication makes use of passwords only, to secure a user account. A multi-factor authentication uses two or more mechanisms for securing user accounts. It ask the question of what the users know (for password), what they have (security token, smart cards), and who they are(biometrics).
The authentication mechanism especially the multi-factor authentication uses three types of authentication form factors.
i. What the entity knows: This includes what the entity knows and can always remember. Such as passwords and PINs
ii. What the entity has: This includes physical items that belong to the entity such as smart cards and token generators.
iii. What the entity really is: This includes natural or body features of the entity such as its thumbprint and its palm which can be used for verification.
According to these three factors, it is evident that password is based on "what an entity knows" and <u>not</u> "what an entity has".
Internal Fragmentation occurs when a process needs more space than the size of allotted memory block or use less space. External Fragmentation occurs when a process is removed from the main memory. Internal Fragmentation occurs when Paging is employed. External Fragmentation occurs when Segmentation is employed.
