The difference between Arrow-finger and Index

Arrow-finger as a noun:

the forefinger

Index as a noun:

An alphabetical listing of items and their location.

Index as a noun:

The index finger; the forefinger.

Index as a noun:

A movable finger on a gauge, scale, etc.

Index as a noun (printing):

A symbol resembling a pointing hand, used to direct particular attention to a note or paragraph.

Index as a noun:

That which points out; that which shows, indicates, manifests, or discloses.

Index as a noun:

A sign; an indication; a token.

Index as a noun (linguistics):

A type of noun where the meaning of the form changes with respect to the context. E.g., 'Today's newspaper' is an indexical form since its referent will differ depending on the context. See also icon and symbol.

Index as a noun (economics):

A single number calculated from an array of prices or of quantities.

Index as a noun (science):

A number representing a property or ratio, a coefficient.

Index as a noun (mathematics):

A raised suffix indicating a power.

Index as a noun (computing, especially, programming, and, databases):

An integer or other key indicating the location of data e.g. within an array, vector, database table, associative array, or hash table.

Index as a noun (computing, databases):

A data structure that improves the performance of operations on a table.

Index as a noun (obsolete):

A prologue indicating what follows.

Index as a verb (transitive):

To arrange an index for something, especially a long text.

Index as a verb:

To inventory, to take stock.

Index as a verb (linguistics, transitive):

To be indexical for (some situation or state of affairs); to indicate.