Often there is mention of limitation period. Please clarify

Limitation period is governed by the Limitation Act which specifies the time limit within which the parties to a legal agreement can take action in a court of law to enforce their legal right. On expiry of limitation period the filing of legal suit is barred. In most bank loan agreements the limitation period is 3 years except in mortgage where it is 12 years

We hear of Negotiable Instruments but are not clear about it. Can you elaborate.

Cheques ,bank drafts, bills of exchange and promissory notes are known as negotiable instruments. Negotiation means transfer of an instrument through endorsement and delivery with the transferee getting better and absolute title provided it is taken in good faith and for value. All bank payments are based on this requirement to be fulfilled.