| List II (Descriptions) | ||
|---|---|---|---|
| A | Free software | I | Users have the freedom to run, copy, change or adapt free software |
| B | Freeware | II | It is a software a user can download from the internet free of charge |
| C | shareware | III | Users are allowed to try out some software free change for a trial period |
| D | Firewall | IV | Helping to prevent viruses or jackers entering the user computer(or internet network) |
A series of instructions that performs a particular task is called __________
